Using the 2D API.

Below is a description, with examples, of most 2D drawing primitives implemented in TGX.

• For additional details, look directly into the main header file Image.h
• Do not forget to check the examples located in the /examples/ subdirectory of the library. In particular, the example TestPrimitives contains all the code listed below.

2D Drawing methods.

Filling the screen.

Code used to generate the image:

tgx::RGB32 buffer[320*240];                     //
tgx::Image<tgx::RGB32> im(buffer, 320, 240);    // create a 320x240 image. 
 
im.fillScreen(tgx::RGB32_Black);                              // same as im.clear(tgx::RGB32_Black);
auto im1 = im(0, 106, 0, 240);                                // create subimage = left third of the image
im1.fillScreenVGradient(tgx::RGB32_Blue, tgx::RGB32_Red);     // fill with vertical gradient from blue to red
auto im2 = im(214, 320, 0, 240);                              // create subimage = right third of the image
im2.fillScreenHGradient(tgx::RGB32_Green, tgx::RGB32_Orange); // fill with horizontal gradient from green to orange

Methods:

• clear() : set all pixels of the image with the same color.
• fillScreen() : same as clear().
• fillScreenVGradient() : fill the image with a vertical gradient between two colors.
• fillScreenHGradient() : fill the image with an horizontal gradient between two colors.

---

Reading/writing pixels

Code used to generate the image:

tgx::RGB32 buffer[320*240];                   //
tgx::Image<tgx::RGB32> im(buffer, 320, 240);  // create a black 320x240 image. 
im.clear(tgx::RGB32_Black);                   //
 
for (int i = 0; i < 310; i += 15) {
    for (int j = 0; j < 230; j += 15){
        im.drawPixel({ i, j }, tgx::RGB32_White);              // integer valued position vector
        im.drawPixelf({ i + 4.4f, j + 5.6f }, tgx::RGB32_Red); // floating-point valued position vector
        im(i+10, j+10) =  tgx::RGB32_Green;                    // direct acces to memory loaction of the pixel. 
        }
    }

Methods:

• drawPixel() : set the color of agiven pixel.
• drawPixelf() : set the color of agiven pixel, use floating point values position vector.
• readpixel() : read the color of a pixel.
• operator() : direct access to the pixel color memory location (read/write).

---

Flood-filling a region

Code used to generate the image:

tgx::RGB32 buffer[320*240];                   //
tgx::Image<tgx::RGB32> im(buffer, 320, 240);  // create a black 320x240 image. 
im.clear(tgx::RGB32_Black);                   //
 
im.drawLine({ 0,50 }, { 320,160 }, tgx::RGB32_White);  
im.drawLine({ 0,240 }, { 320,10 }, tgx::RGB32_Red);
im.fill({ 319,239 }, tgx::RGB32_Red, tgx::RGB32_Blue); // fill starting {319,239}, region delimited by the red line
im.fill({ 0,0 }, tgx::RGB32_Olive);                    // fill starting {0,0}

Methods:

• fill(start_pos, new_color) : fill a connected componenet with a given color.
• fill(start_pos, border_color, new_color) : fill a region delimited by a given color.

---

Blitting sprites

Code used to generate the image:

// create a sprite: 
// #include <font_tgx_OpenSans_Bold.h> is needed to use the font_tgx_Arial_Bold_20. 
tgx::RGB32 buf[120 * 40]; // memory for the sprite image
tgx::Image<tgx::RGB32> sprite(buf, 120, 40); // the sprite image...
sprite.clear(tgx::RGB32_Green); // ... has green background
sprite.fillCircle({ 20, 20 }, 13, tgx::RGB32_Black, tgx::RGB32_Black); // ... a black circle
sprite.drawTextEx("Sprite", { 76, 20 }, font_tgx_Arial_Bold_20, tgx::Anchor::CENTER, false, false, tgx::RGB32_Black); // ... and a black text "sprite".
 
im.fillScreenHGradient(tgx::RGB32_Blue, tgx::RGB32_Red); // fill the screen with horizontal gradient from green to orange
 
im.blit(sprite, { 10, 10 });  // simple blitting
im.blitRotated(sprite, { 10, 80 }, 270, 0.25f); // blit the sprite rotated by 270 degrees clockwise, 0.25% opacity
im.blitMasked(sprite, tgx::RGB32_Black, { 120,60 }); // blit the sprite with black as a the transparent color.
im.blitScaledRotated(sprite, { 60, 20 }, { 100, 160 }, 0.6f, 60.0f, 0.5f); // blit the sprite scaled at 0.6, rotated by 60 degrees, half opacity
im.blitScaledRotatedMasked(sprite, tgx::RGB32_Green, { 60, 20 }, { 230, 160 }, 1.5f, -25.0f); // blit the sprite scaled at 1.5, rotated by -25 degrees, with green set as the transparent color.

Methods:

• blit(sprite, pos, opacity) : blit a sprite image onto the image.
• blitRotated(sprite, pos, angle, opacity) : rotate a sprite (by quarter turns) and then blit it onto the image.
• blitMasked(sprite, mask_color, pos, opacity) : blit a sprite onto the image with one color set as transparent.
• blitScaledRotated(sprite, pos_src, pos_dst, scale, angle, opacity) : rescale and rotate a sprite (by arbitrary angle) and then blit it onto the image.
• blitScaledRotatedMasked(sprite, mask_color, pos_src, pos_dst, scale, angle, opacity) : rescale and rotate a sprite (by arbitrary angle) and then blit it onto the image with one color set as transparent.

Note

All the blit methods above also have an 'advanced' version which takes as input a user-defined blending operator instead of the opacity parameter and can operate on sprites with a different color types than the destination image. see tgx::Image for details...

See also blitBackward() and methods for image copy/resizing/type conversion copyFrom(), copyReduceHalf(), reduceHalf() and convert()

---

drawing horizontal and vertical lines

Code used to generate the image:

tgx::RGB32 buffer[320*240];                   //
tgx::Image<tgx::RGB32> im(buffer, 320, 240);  // create a black 320x240 image. 
im.clear(tgx::RGB32_Black);                   //
 
for (int i = 0; i < 20; i++) {
    im.drawFastVLine({ i * 16, i * 3 }, 100, tgx::RGB32_Red, i / 20.0f);    // draw a vertical line
    im.drawFastHLine({ i * 3, i * 12 }, 200, tgx::RGB32_Green, i / 20.0f);  // draw an horizontal line
    }

Methods: use these methods when drawing parallel lines as they are faster that the 'general' line drawing methods.

• drawFastVLine() : draw a vertical line segment.
• drawFastHLine() : draw an horizontal line segment.

---

drawing lines

Code used to generate the image:

tgx::RGB32 buffer[320*240];                   //
tgx::Image<tgx::RGB32> im(buffer, 320, 240);  // create a black 320x240 image. 
im.clear(tgx::RGB32_Black);                   //
 
im.drawLine({ 10,10 }, { 300, 60 }, tgx::RGB32_Red);       // simple red line
im.drawLineAA({ 200,200 }, { 300, 10 }, tgx::RGB32_Green); // green line with anti-aliasing
im.drawThickLineAA({ 10, 120 }, { 250, 10 }, 10, tgx::END_STRAIGHT, tgx::END_ROUNDED, tgx::RGB32_White); // thick line, rounded at the start, straight at the end.
im.drawWedgeLineAA({ 300, 220 }, { 150, 100 }, 10, tgx::END_ARROW_1, 20, tgx::END_ARROW_SKEWED_5,tgx::RGB32_Orange, 0.5f); // wedge line ending with arrows, half opacity.

Methods:

• drawLine() : draw a basic straight line (single pixel thick, no anti-aliasing). Fastest method.
• drawLineAA() : draw a line segment with anti-aliasing (single pixel thick).
• drawThickLineAA() : draw a thick line with anti-aliasing and specify how the ends look like (rounded, flat, arrows...)
• drawWedgeLineAA() : draw a line segment with anti-aliasing with vraying thickness, specify how the ends look like (rounded, flat, arrows...)

---

drawing rectangles

Code used to generate the image:

tgx::RGB32 buffer[320*240];                   //
tgx::Image<tgx::RGB32> im(buffer, 320, 240);  // create a black 320x240 image. 
im.clear(tgx::RGB32_Black);                   //
 
im.drawRect({ 10,70,10,70 }, tgx::RGB32_White); // simple green square, full opacity
im.drawThickRect({ 30,180,30,140 }, 7,  tgx::RGB32_Orange, 0.5f); // 7 pixels thick orange rectangle, half opacity
im.fillRect({5, 80, 20, 200}, tgx::RGB32_Yellow, 0.25f); // yellow filled rectangle, 25% opacity
im.fillThickRect({ 50, 150, 150, 220 }, 5, tgx::RGB32_Gray, tgx::RGB32_Red, 0.5f); // gray filled, 5 pixels thick red rectangle, 50% opacity
im.fillRectHGradient({ 140, 310, 100, 160 }, tgx::RGB32_Red, tgx::RGB32_Blue); // rectangle filled with horizontal gradient from red to blue. full opacity.
im.fillRectVGradient({ 190, 300, 10, 230 }, tgx::RGB32_Cyan, tgx::RGB32_Purple, 0.5f); // rectangle filled with vertical gradient from cyan to purple. half opacity.

Methods:

• drawRect() : draw a basic rectangle. Fastest method.
• drawThickRect() : draw a rectangle with a thick outline.
• fillRect() : draw a filled rectangle.
• fillThickRect() : draw a filled rectangle with a thick outline of a different color.
• fillRectHGradient() : draw a filled rectangle with an horizontal gradient between two colors.
• fillRectVGradient() : draw a filled rectangle with a vertical gradient between two colors.

See also drawThickRectAA(), drawThickRectAA(), drawThickRectAA(). These methods may be useful for smooth animations but usually not for static display (as rectangles egdes are parallel to pixel boundaries hence do not usually require anti-aliasing).

---

drawing rounded rectangles

Code used to generate the image:

tgx::RGB32 buffer[320*240];                   //
tgx::Image<tgx::RGB32> im(buffer, 320, 240);  // create a black 320x240 image. 
im.clear(tgx::RGB32_Black);                   //
 
im.drawRoundRectAA({ 10,70,10,70}, 4, tgx::RGB32_White); // simple 4-pixels rounded square
im.drawThickRoundRectAA({ 30,180,30,140 }, 20, 7, tgx::RGB32_Orange, 0.5f); // 7 pixels thick, 20 pixels rounded corner rectangle, half opacity
im.fillRoundRectAA({ 140, 310, 170, 230 }, 25, tgx::RGB32_Blue); // filled 25-pixel rounded corner rectangle
im.fillThickRoundRectAA({ 100, 250, 60, 200 }, 10, 5, tgx::RGB32_Gray, tgx::RGB32_Red, 0.5f); // 5 pixels thick, 10 pixel rounded corner rectangle, 50% opacity

Methods:

• drawRoundRectAA() : draw a single pixel thick rectangle with rounded corners, with antiliasing.
• drawThickRoundRectAA() : draw a rounded corners rectangle with thick outline, with antiliasing.
• fillRoundRectAA() : draw a filled rectangle with rounded corners, with anti-aliasing.
• fillThickRoundRectAA() : draw a filled rectangle with rounded corners and thick outline of a different color, with anti-aliasing.

---

drawing triangles

Code used to generate the image:

tgx::RGB32 buffer[320*240];                   //
tgx::Image<tgx::RGB32> im(buffer, 320, 240);  // create a black 320x240 image. 
im.clear(tgx::RGB32_Black);                   //
 
im.drawTriangle({ 10,10 }, { 60, 30 }, {40, 80}, tgx::RGB32_White); // simple triangle
im.fillTriangle({150, 5}, {80, 180}, {300, 20} , tgx::RGB32_Purple, tgx::RGB32_Magenta); // filled triangle with border
im.drawTriangleAA({ 20,120 }, { 150, 100 }, { 70, 239}, tgx::RGB32_Green); // green triangle with AA
im.drawThickTriangleAA({ 160, 60 }, {240,30}, {300, 80}, 10, tgx::RGB32_Cyan, 0.5f); // 10 pixels thick triangle, 50% opacity, with AA
im.fillTriangleAA({ 200, 220 }, { 315,210 }, { 150, 120 }, tgx::RGB32_Yellow); // filled triangle with AA.
im.fillThickTriangleAA({ 130,200 }, { 280, 110 }, {250, 170}, 5, tgx::RGB32_Lime, tgx::RGB32_Orange, 0.5f); // filled 5 pixels thick triangle, 50% opacity, with AA

Methods:

• drawTriangle() : draw a simple triangle. Fastest method.
• fillTriangle() : draw a simple filled triangle. Fastest method
• drawTriangleAA() : draw a triangle with single pixel thick outline, with anti-aliasing.
• drawThickTriangleAA() : draw a triangle with thick outline, with anti-aliasing.
• fillTriangleAA() : draw a filled triangle with anti-aliasing.
• fillThickTriangleAA() : draw a filled triangle with a thick outline of a different color, with anti-aliasing.

---

drawing triangles (advanced)

Code used to generate the image:

tgx::RGB32 buffer[320*240];                   //
tgx::Image<tgx::RGB32> im(buffer, 320, 240);  // create a black 320x240 image. 
im.clear(tgx::RGB32_Black);                   //
 
tgx::RGB32 buf[50 * 50]; // memory for texture image
tgx::Image<tgx::RGB32> tex(buf, 50, 50); // the texture image...
tex.clear(tgx::RGB32_Blue); // ... has blue background ..
tex.fillThickCircleAA({ 25,25 }, 24, 5, tgx::RGB32_Red, tgx::RGB32_Green); // ...and red-filled circle with green outline in the center. 
 
im.drawTexturedTriangle(tex, { 0,0 }, { 50, 0 }, { 50, 50 }, { 10, 10 }, { 100, 20 }, { 30, 100 }); // textured triangle, full opacity
im.drawGradientTriangle({ 20, 140 }, { 160, 50 }, {230, 200}, tgx::RGB32_Blue, tgx::RGB32_Orange, tgx::RGB32_Black); // gradient triangle, full opacity. 
im.drawTexturedGradientTriangle(tex, { 0,0 }, { 50, 0 }, { 50, 50 } , { 120, 230 }, { 300, 20 }, { 280, 170 }, tgx::RGB32_Red, tgx::RGB32_Green, tgx::RGB32_Blue, 0.5f); // texture triangle with color gradient. half opacity.

Methods: these methods make use of the 3D rasterizer:

• drawTexturedTriangle() : draw a filled triangle with texture mapping.
• drawGradientTriangle() : draw a filled triangle with gradient color (i.e. Gouraud shading)
• drawTexturedGradientTriangle() : draw a filled trinagle with both texture mapping and gradient color.

See also drawTexturedMaskedTriangle(), drawTexturedGradientMaskedTriangle() for additonal masking features.

---

drawing quads

Code used to generate the image:

tgx::RGB32 buffer[320*240];                   //
tgx::Image<tgx::RGB32> im(buffer, 320, 240);  // create a black 320x240 image. 
im.clear(tgx::RGB32_Black);                   //
 
im.drawQuad({ 10,10 }, { 60, 30 }, { 40, 80 }, {5, 40}, tgx::RGB32_White); // simple quad
im.fillQuad({ 150, 5 }, { 80, 180 }, {170, 40}, { 300, 20 }, tgx::RGB32_Purple); // filled quad
im.drawQuadAA({ 20,120 }, { 150, 100 }, { 150, 140 },  { 70, 239 }, tgx::RGB32_Green); // green quad with AA
im.drawThickQuadAA({ 160, 60 }, { 240,30 }, { 300, 80 }, {230, 120}, 10, tgx::RGB32_Cyan, 0.5f); // 10 pixels thick quad, 50% opacity, with AA
im.fillQuadAA({ 200, 220 }, { 315,210 }, {250, 150}, { 150, 120 }, tgx::RGB32_Yellow); // filled quad with AA
im.fillThickQuadAA({ 130,200 }, { 160, 140 }, { 230, 100 }, { 250, 170 } , 5, tgx::RGB32_Lime, tgx::RGB32_Orange, 0.5f); //filled, 5 pixels thick quad, 50% opacity, with AA

Methods:

• drawQuad() : draw a simple quad. Fastest method.
• fillQuad() : draw a simple filled quad. Fastest method
• drawQuadAA() : draw a quad with single pixel thick outline, with anti-aliasing.
• drawThickQuadAA() : draw a quad with thick outline, with anti-aliasing.
• fillQuadAA() : draw a filled quad with anti-aliasing.
• fillThickQuadAA() : draw a filled quad with a thick outline of a different color, with anti-aliasing.

---

drawing quads (advanced)

Code used to generate the image:

tgx::RGB32 buffer[320*240];                   //
tgx::Image<tgx::RGB32> im(buffer, 320, 240);  // create a black 320x240 image. 
im.clear(tgx::RGB32_Black);                   //
 
im.drawTexturedQuad(tex, { 0,0 }, { 50, 0 }, { 50, 50 }, { 0, 50 }, { 10, 10 }, { 100, 20 }, { 80, 40 }, {30, 120}); // textured quad, 
im.drawGradientQuad({ 20, 140 }, { 160, 50 }, {180, 55}, { 230, 200 }, tgx::RGB32_Blue, tgx::RGB32_Orange, tgx::RGB32_Green, tgx::RGB32_Black); // gradient quad
im.drawTexturedGradientQuad(tex, { 0,0 }, { 50, 0 }, { 50, 50 }, { 0, 50 }, { 120, 230 }, { 280, 20 }, { 310, 170 }, {250,210}, tgx::RGB32_Red, tgx::RGB32_Green, tgx::RGB32_Blue, tgx::RGB32_Navy,0.5f); // texture quad with color gradient. half opacity.

Methods: these methods make use of the 3D rasterizer:

• drawTexturedQuad() : draw a filled quad with texture mapping.
• drawGradientQuad() : draw a filled quad with gradient color (i.e. Gouraud shading)
• drawTexturedGradientQuad() : draw a filled quad with both texture mapping and gradient color.

See also drawTexturedMaskedQuad(), drawTexturedGradientMaskedQuad() for additonal masking features.

---

drawing polylines

Code used to generate the image:

tgx::RGB32 buffer[320*240];                   //
tgx::Image<tgx::RGB32> im(buffer, 320, 240);  // create a black 320x240 image. 
im.clear(tgx::RGB32_Black);                   //
 
const tgx::iVec2 tabPoints1[] = { {10, 10}, {50, 10}, {80, 50}, {20, 110}, {20, 180}, {300, 150} };
im.drawPolyline(6, tabPoints1, tgx::RGB32_White); // simple polyline
 
const tgx::fVec2 tabPoints2[] = { {200, 100}, {100, 20}, {130, 120}, {10, 200}, {60, 180}, {300, 230} };
im.drawPolylineAA(6, tabPoints2, tgx::RGB32_Red); // polyline with AA
 
const tgx::fVec2 tabPoints3[] = { {30, 30}, {200, 15}, {300, 200}, {140, 230}, {80, 150}, {20, 230} };
im.drawThickPolylineAA(6, tabPoints3, 12, tgx::END_ARROW_1, tgx::END_ROUNDED, tgx::RGB32_Orange, 0.5f); // thick polyline, arrow at start, rounded at end, half opacity, with AA

Methods:

• drawPolyline() : draw a simple polyline. Fastest method.
• drawPolylineAA() : draw a polyline, with anti-aliasing.
• drawThickPolylineAA() : draw a thick polyline with anti-aliasing and specify how the ending look like.

---

drawing polygons

Code used to generate the image:

tgx::RGB32 buffer[320*240];                   //
tgx::Image<tgx::RGB32> im(buffer, 320, 240);  // create a black 320x240 image. 
im.clear(tgx::RGB32_Black);                   //
 
tgx::iVec2 tabPoints1[] = { {10, 10}, {50, 10}, {80, 40}, {50, 90}, {10, 70} };
im.drawPolygon(5, tabPoints1, tgx::RGB32_White); // simple polygon
 
tgx::iVec2 tabPoints2[] = { {90, 20}, {50, 40}, {60, 80}, {150, 90}, {190, 45} };
im.fillPolygon(5, tabPoints2, tgx::RGB32_Yellow, 0.5f); // filled polygon, half opacity.
 
tgx::fVec2 tabPoints3[] = { {140, 60}, {250, 10}, {310, 100}, {300, 150}, {240, 170}, {220, 120} };
im.drawPolygonAA(6, tabPoints3, tgx::RGB32_Red); // polygon with AA
 
tgx::fVec2 tabPoints4[] = { {10, 120}, {50, 80}, {100, 150}, {40, 200}, {50, 170} };
im.drawThickPolygonAA(5, tabPoints4, 6, tgx::RGB32_Cyan, 0.5f); // thick polygon, 50% opacity, with AA
 
tgx::fVec2 tabPoints5[] = { {50, 120}, {130, 70}, {170, 100}, {210, 180}, {150, 190} };
im.fillPolygonAA(5, tabPoints5, tgx::RGB32_Lime, 0.5f); // filled polygon, 50% opacity, with AA
 
tgx::fVec2 tabPoints6[] = { {120, 150}, {210, 50}, {250, 70}, {300, 100}, {290, 170}, {230, 210} };
im.fillThickPolygonAA(6, tabPoints6, 10, tgx::RGB32_Purple, tgx::RGB32_Orange, 0.5f); // filled thick polygon, 50% opacity, with AA

Methods:

• drawPolygon() : draw a simple polygon. Fastest method.
• fillPolygon() : draw a simple filled polygon. Fastest method.
• drawPolygonAA() : draw a polygon with anti-aliasing.
• drawThickPolygonAA() : draw a polygon with thick outline, with anti-aliasing.
• fillPolygonAA() : draw a filled polygon, with anti-aliasing.
• fillThickPolygonAA() : draw a filled polygon with thick outline, with anti-aliasing.

---

drawing circles

Code used to generate the image:

tgx::RGB32 buffer[320*240];                   //
tgx::Image<tgx::RGB32> im(buffer, 320, 240);  // create a black 320x240 image. 
im.clear(tgx::RGB32_Black);                   //
 
im.drawCircle({50, 50}, 48, tgx::RGB32_White); // simple circle
im.fillCircle({ 120, 80 }, 70, tgx::RGB32_Blue, tgx::RGB32_Red, 0.5f); // filled circle, 50% opacity
im.drawCircleAA({210, 90}, 60, tgx::RGB32_Green); // green circle with AA
im.drawThickCircleAA({60, 180}, 40, 10, tgx::RGB32_Purple); //thick maroon circle, with AA
im.fillCircleAA({230, 150}, 70, tgx::RGB32_Yellow, 0.5f); // filled circle with AA, 50% opacity
im.fillThickCircleAA({160,160}, 55, 8, tgx::RGB32_Teal, tgx::RGB32_Orange, 0.5f); // filled circle with thick outline, with AA, 50% opacity 

Methods:

• drawCircle() : draw a simple circle. Fastest method.
• fillCircle() : draw a simple filled circle. Fastest method.
• drawCircleAA() : draw a circle with anti-aliasing.
• drawThickCircleAA() : draw a circle with thick outline, with anti-aliasing.
• fillCircleAA() : draw a filled circle, with anti-aliasing.
• fillThickCircleAA() : draw a filled circle with thick outline, with anti-aliasing.

---

drawing ellipses

Code used to generate the image:

tgx::RGB32 buffer[320*240];                   //
tgx::Image<tgx::RGB32> im(buffer, 320, 240);  // create a black 320x240 image. 
im.clear(tgx::RGB32_Black);                   //
 
im.drawEllipse({ 50, 50 }, { 48, 20 }, tgx::RGB32_White); // simple ellipse
im.fillEllipse({ 120, 80 }, { 70, 50 }, tgx::RGB32_Blue, tgx::RGB32_Red, 0.5f); // filled ellipse, 50% opacity
im.drawEllipseAA({ 210, 90 }, { 60, 30 }, tgx::RGB32_Green); // ellipse with AA
im.drawThickEllipseAA({ 60, 180 }, { 35, 55 }, 10, tgx::RGB32_Purple); // thick ellipse, with AA
im.fillEllipseAA({ 230, 150 }, { 45, 70 }, tgx::RGB32_Yellow, 0.5f); // filled ellipse with AA, 50% opacity
im.fillThickEllipseAA({ 160,160 }, { 55, 65 }, 8, tgx::RGB32_Teal, tgx::RGB32_Orange, 0.5f); // filled ellipse with thick outline, with AA, 50% opacity 

Methods:

• drawEllipse() : draw a simple ellipse. Fastest method.
• fillEllipse() : draw a simple filled ellipse. Fastest method.
• drawEllipseAA() : draw an ellipse with anti-aliasing.
• drawThickEllipseAA() : draw an ellipse with thick outline, with anti-aliasing.
• fillEllipseAA() : draw a filled ellipse, with anti-aliasing.
• fillThickEllipseAA() : draw a filled ellipse with thick outline, with anti-aliasing.

---

drawing circle arcs and pies

Code used to generate the image:

tgx::RGB32 buffer[320*240];                   //
tgx::Image<tgx::RGB32> im(buffer, 320, 240);  // create a black 320x240 image. 
im.clear(tgx::RGB32_Black);                   //
 
im.fillCircleSectorAA({ 60,60 }, 40, 50, 270, tgx::RGB32_Red); // filled circle sector between 50 and 270 degrees
im.drawCircleArcAA({250, 60}, 50, 250, 90, tgx::RGB32_Green); // green circle arc from 250 to 90 degrees
im.drawThickCircleArcAA({80, 160}, 75, 220, 160, 20, tgx::RGB32_Purple, 0.5f); // thick circle arc from 220 to 160 degrees, 50% opacity
im.fillThickCircleSectorAA({230, 120}, 100, 140, 340, 10, tgx::RGB32_Olive, tgx::RGB32_Orange, 0.5f); // filled thick circle sector from 140 to 340 degrees, 50% opacity

Methods:

• fillCircleSectorAA() : draw a circle sector (pie), with AA.
• drawCircleArcAA() : draw a circle arc, single pixel thickness, with AA
• drawThickCircleArcAA() : draw a thick circle arc, with AA
• fillThickCircleSectorAA() : draw a circle sector (pie) with thick outline (circle arc), with AA.

---

drawing Bezier curves

Code used to generate the image:

tgx::RGB32 buffer[320*240];                   //
tgx::Image<tgx::RGB32> im(buffer, 320, 240);  // create a black 320x240 image. 
im.clear(tgx::RGB32_Black);                   //
 
im.drawQuadBezier({ 10, 10 }, { 250, 180 }, {280, 20}, 1.0f, true, tgx::RGB32_White); // simple quadratic bezier curve
im.drawCubicBezier({ 10, 40 }, { 280, 50 }, { 20, 80 }, { 300, 200 }, true, tgx::RGB32_Green); // simple cubic bezier curve
im.drawThickQuadBezierAA({ 30, 150 }, { 300, 20 }, {0,0}, 2.0f, 10, tgx::END_STRAIGHT, tgx::END_ROUNDED, tgx::RGB32_Red, 0.5f); // thick quadratic bezier curve, with AA, 50% opacity.
im.drawThickCubicBezierAA({ 80, 80 }, { 305, 150 }, { 0, 240 }, {290, 240}, 10, tgx::END_ARROW_5, tgx::END_ARROW_SKEWED_2, tgx::RGB32_Orange, 0.5f); // thick cubic bezier curve, with AA, 50% opacity.

Methods:

• drawQuadBezier() : draw a quadratic Bezier curve.
• drawCubicBezier() : draw a cubic Bezier curve.
• drawThickQuadBezierAA() : draw a thick quadratic Bezier curve, with AA
• drawThickCubicBezierAA() : draw a thick cubic Bezier curve, with AA.

---

drawing splines

Code used to generate the image:

tgx::RGB32 buffer[320*240];                   //
tgx::Image<tgx::RGB32> im(buffer, 320, 240);  // create a black 320x240 image. 
im.clear(tgx::RGB32_Black);                   //
 
const tgx::iVec2 tabPoints1[] = { {30, 10}, {10, 40}, {40, 70}, {10, 100}, {60, 130}, {10, 160}, {80, 190}, {10, 220} };
im.drawQuadSpline(8, tabPoints1, true, tgx::RGB32_White); // simple quadratic spline
    
const tgx::iVec2 tabPoints2[] = { {10, 10}, {50, 40}, {10, 70}, {70, 100}, {10, 130}, {90, 160}, {10, 190}, {120, 220} };
im.drawCubicSpline(8, tabPoints2, true, tgx::RGB32_Red); // simple cubic spline
 
const tgx::fVec2 tabPoints3[] = { {70, 10}, {40, 40}, {80, 70}, {30, 100}, {120, 130}, {60, 160}, {150, 190}, {80, 220} };
im.drawThickQuadSplineAA(8, tabPoints3, 5, tgx::END_ROUNDED, tgx::END_ROUNDED, tgx::RGB32_Yellow, 0.5f); // thick quadratic spline, 50% opacity, with AA
 
const tgx::fVec2 tabPoints4[] = { {60, 20}, {120, 40}, {50, 70}, {130, 100}, {60, 130}, {110, 160}, {70, 190}, {60, 220} };
im.drawThickCubicSplineAA(8, tabPoints4, 6, tgx::END_ARROW_3, tgx::END_ARROW_SKEWED_3, tgx::RGB32_Green, 0.5f); // thick cubic spline, 50% opacity, with AA
 
const tgx::fVec2 tabPoints5[] = { {140, 20}, {160, 10}, {200, 50}, {250, 20}, {300, 100}, {250, 160}, {200, 100}, {160, 150} };
im.drawThickClosedSplineAA(8, tabPoints5, 12, tgx::RGB32_Blue); // thick closed spline, with AA
 
const tgx::iVec2 tabPoints6[] = { {240, 10}, {310, 50}, {200, 130} };
im.drawClosedSpline(3, tabPoints6, tgx::RGB32_Magenta, 0.5f); // simple closed spline, 50% opacity
 
const tgx::fVec2 tabPoints7[] = { {300, 220}, {240, 220}, {240, 180}, {300, 190} };
im.fillClosedSplineAA(4, tabPoints7, tgx::RGB32_Cyan); // interior filled closed spline, with AA
 
const tgx::fVec2 tabPoints8[] = { {150, 210}, {160, 150}, {250, 120}, {280, 150}, {260, 190} };
im.fillThickClosedSplineAA(5, tabPoints8, 5, tgx::RGB32_Gray ,tgx::RGB32_Red, 0.5f); // interior filled thick closed spline, 50% opacity, with AA

Methods:

• drawQuadSpline() : draw a simple quadratic spline
• drawCubicSpline() : draw a simple cubic spline
• drawThickQuadSplineAA() : draw a thick quadratic spline, with AA
• drawThickCubicSplineAA() : draw a thick cubic spline, with AA
• drawThickClosedSplineAA() : draw a thick closed spline, with AA
• drawClosedSpline() : draw a simple thick closed spline
• fillClosedSplineAA() : draw a closed spline and fill its interior, with AA
• fillThickClosedSplineAA() : draw a thick closed spline and fill its interior, with AA

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drawing text

additional includes for the text fonts

#include "font_tgx_Arial.h"
#include "font_tgx_OpenSans.h"

Code used to generate the image:

tgx::RGB32 buffer[320*240];                   //
tgx::Image<tgx::RGB32> im(buffer, 320, 240);  // create a black 320x240 image. 
im.clear(tgx::RGB32_Black);                   //
 
// drawing text: the anchor point use the baseline. 
im.drawText("non-AA font are ugly...", { 5, 10 },font_tgx_Arial_8, tgx::RGB32_Blue); // a non AA font
im.drawText("AA font, 9pt", { 5, 25 }, font_tgx_OpenSans_9, tgx::RGB32_Green);     // AA font, 9pt
im.drawText("AA font, 10pt", { 5, 40 }, font_tgx_OpenSans_10, tgx::RGB32_Green);   // AA font, 10pt
im.drawText("AA font, 14pt", { 5, 60 }, font_tgx_OpenSans_14, tgx::RGB32_Green);   // AA font, 14pt
im.drawText("AA font, 18pt", { 5, 83 }, font_tgx_OpenSans_20, tgx::RGB32_Green);   // AA font, 18pt
 
// drawing on the baseline
im.drawFastHLine({ 130, 30 }, 160, tgx::RGB32_White, 0.5f);
im.drawFastHLine({ 130, 45 }, 160, tgx::RGB32_White, 0.5f);
im.drawText("The quick brown fox jumps", { 130, 30 }, font_tgx_OpenSans_12, tgx::RGB32_Orange);
im.drawText("over the lazy dog !", { 130, 45 }, font_tgx_OpenSans_12, tgx::RGB32_Orange);
 
// finding the bounding box of a text. 
const char * tbb = "Text bounding box";
tgx::iBox2 bb = im.measureText(tbb, { 230, 70 }, font_tgx_OpenSans_14, tgx::Anchor::CENTER, false, false);
im.fillRect(bb, tgx::RGB32_Yellow, 0.5f);
im.drawTextEx(tbb, { 230, 70 }, font_tgx_OpenSans_14, tgx::Anchor::CENTER, false, false, tgx::RGB32_Blue);
 
 
// draw text with different anchor points using drawTextEx()
// -> the anchor is relative to the text bounding box
im.drawRect({ 20, 300,100, 230 }, tgx::RGB32_Gray);
im.drawFastHLine({ 20, 165 }, 280, tgx::RGB32_Gray);
im.drawFastVLine({ 160, 100 }, 130, tgx::RGB32_Gray);
tgx::iVec2 anchor_point;
 
anchor_point = {20, 100 };
im.drawTextEx("TOPLEFT", anchor_point, font_tgx_OpenSans_10, tgx::Anchor::TOPLEFT, true, true, tgx::RGB32_Red);
im.fillCircleAA(anchor_point,1.5, tgx::RGB32_Green);
 
anchor_point = { 300, 100 };
im.drawTextEx("TOPRIGHT", anchor_point, font_tgx_OpenSans_10, tgx::Anchor::TOPRIGHT, true, true, tgx::RGB32_Red);
im.fillCircleAA(anchor_point, 1.5, tgx::RGB32_Green);
 
anchor_point = { 20, 230 };
im.drawTextEx("BOTTOMLEFT", anchor_point, font_tgx_OpenSans_10, tgx::Anchor::BOTTOMLEFT, true, true, tgx::RGB32_Red);
im.fillCircleAA(anchor_point, 1.5, tgx::RGB32_Green);
 
anchor_point = { 300, 230 };
im.drawTextEx("BOTTOMRIGHT", anchor_point, font_tgx_OpenSans_10, tgx::Anchor::BOTTOMRIGHT, true, true, tgx::RGB32_Red);
im.fillCircleAA(anchor_point, 1.5, tgx::RGB32_Green);
 
anchor_point = { 160, 100 };
im.drawTextEx("CENTERTOP", anchor_point, font_tgx_OpenSans_10, tgx::Anchor::CENTERTOP, true, true, tgx::RGB32_Red);
im.fillCircleAA(anchor_point, 1.5, tgx::RGB32_Green);
 
anchor_point = { 160, 230 };
im.drawTextEx("CENTERBOTTOM", anchor_point, font_tgx_OpenSans_10, tgx::Anchor::CENTERBOTTOM, true, true, tgx::RGB32_Red);
im.fillCircleAA(anchor_point, 1.5, tgx::RGB32_Green);
 
anchor_point = { 20, 165 };
im.drawTextEx("CENTERLEFT", anchor_point, font_tgx_OpenSans_10, tgx::Anchor::CENTERLEFT, true, true, tgx::RGB32_Red);
im.fillCircleAA(anchor_point, 1.5, tgx::RGB32_Green);
 
anchor_point = { 300, 165 };
im.drawTextEx("CENTERRIGHT", anchor_point, font_tgx_OpenSans_10, tgx::Anchor::CENTERRIGHT, true, true, tgx::RGB32_Red);
im.fillCircleAA(anchor_point, 1.5, tgx::RGB32_Green);
 
anchor_point = { 160, 165 };
im.drawTextEx("CENTER", anchor_point, font_tgx_OpenSans_10, tgx::Anchor::CENTER, true, true, tgx::RGB32_Red);
im.fillCircleAA(anchor_point, 1.5, tgx::RGB32_Green);

The TGX library support font using:

• AdafruitGFX format: (https://learn.adafruit.com/adafruit-gfx-graphics-library/using-fonts)
• ILI9341_t3 v1 format (https://forum.pjrc.com/threads/54316-ILI9341_t-font-structure-format)
• ILI9341_t3 v23 format (antialiased) (https://github.com/projectitis/packedbdf/blob/master/packedbdf.md)

Note

tgx-font (https://github.com/vindar/tgx-font) contains a collection ILI9341_t3 v1 and v2 (antialiased) fonts that can be used directly with the methods below (and instructions on how to convert a ttf font to this format).

The following fonts are already packaged with TGX but must be included explicitely in the project when used:

• Arial (non AA font): #include "font_tgx_Arial.h"
• Arial Bold (non AA font): #include "font_tgx_Arial_Bold.h"
• OpenSans (AA font): #include "font_tgx_OpenSans.h"
• OpenSans Bold (AA font): #include "font_tgx_OpenSans_Bold.h"
• OpenSans Italic (AA font): #include "font_tgx_OpenSans_Italic.h"

Each font above is available in fontsize: 8pt, 9pt, 10pt, 11pt, 12pt, 13pt, 14pt, 16pt, 18pt, 20pt, 24pt, 28pt, 32pt, 40pt, 48pt, 60pt, 72pt, 96pt.

Methods:

• drawText() : draw a text using a given font. simple "legacy" method
• drawTextEx() : draw a text using a given font. Extended method with anchor placement (c.f. tgx::Anchor).
• measureText() : compute the bounding box of a text (fast, does not draw it)
• measureChar() : compute the bounding box of a character (fast, does not draw it)

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TGX extensions via external librairies

TGX implements bindings that makes it easy to use external libraries to add new capabilities to the Image class, such as displaying classic image format (PNG, GIF, JPEG) and TrueType fonts...

Drawing text with TrueType fonts

Install Takkao's OpenRenderFont library from https://github.com/takkaO/OpenFontRender/.

Simply include both libraries into the project to activate the bindings between TGX and OpenFontRender:

#include <tgx.h>
#include <OpenFontRender.h>

Now, we can bind any OpenFontRender object to an image with the method: Image::setOpenFontRender(ofr) and subsequently use the OpenFontRender library as usual. All texts written with ofr will automatically be drawn onto the selected image.

Example:

// create a 100x50 image in RGB565 color format. 
tgx::RGB565 buf[100*50];
tgx::Image<tgx::RGB565> im(buf, 100, 50);
im.clear(tgx::RGB565_Black); // clear to full black
 
// create a font rendering object
OpenFontRender ofr; 
 
// we link it wih image im
im.setOpenFontRender(ofr); 
 
// set up the font rendering object properties before drawing
ofr.loadFont(NotoSans_Bold, sizeof(NotoSans_Bold))  // assume here that NotoSans_Bold is a Truetype font in memory. 
ofr.setFontColor((uint16_t)tgx::RGB565_Yellow, (uint16_t)tgx::RGB565_Black); // set foreground and background colors for drawing text
ofr.setCursor(10, 20); // Set the cursor position
ofr.setFontSize(15); // set font size. 
 
// and let's draw text !
ofr.cprintf("Hello World"); // -> drawing in done ont im. 

Note

A complete example is available in the subfolder /examples/Teensy4/OpenFontRender_test/.

Check the OpenfontRender documentation for additional details.

Drawing PNG images

Install Bitbank2's PNGdec library from the Arduino library manager / platformio or directly from https://github.com/bitbank2/PNGdec/.

Simply include both libraries into the project to activate the bindings between TGX and PNGdec:

#include <tgx.h>
#include <PNGdec.h>

Now, we can bind any PNG decoder object tgx images by providing it with the generic callback TGX_PNGDraw and then we can susequently decode PNGs using the Image::PNGDecode() method.

Example:

// create a 150x100 image in RGB565 color format. 
tgx::RGB565 buf[150*100];
tgx::Image<tgx::RGB565> im(buf, 150, 100);
im.clear(tgx::RGB565_Black); // clear to full black
 
// PNG decoder object from PNGdec library
PNG png; 
 
// Load the png image "octocat_4bpp" stored in RAM and link the decoder to TGX
// -> note that 'TGX_PNGDraw' is passed as callback parameter.
png.openRAM((uint8_t*)octocat_4bpp, sizeof(octocat_4bpp), TGX_PNGDraw); 
 
// Draw the PNG onto im, with half opacity and upper left corner at pos (20, 10) inside im. 
im.PNGDecode(png, {20, 10}, 0.5f);

Note

A complete example is available in the subfolder /examples/Teensy4/PNG_test/.

Check the PNGdec documentation for additional details.

Drawing JPEG images

Install Bitbank2's JPEGDEC library from the Arduino library manager / platformio or directly from https://github.com/bitbank2/JPEGDEC.

Simply include both libraries into the project to activate the bindings between TGX and JPEGDEC:

#include <tgx.h>
#include <JPEGDEC.h>

Now, we can bind any JPEGDEC decoder object tgx images by providing it with the generic callback TGX_JPEGDraw and then we can susequently decode JPEGs using the Image::JPEGDecode() method.

Example:

// create a 150x100 image in RGB565 color format. 
tgx::RGB565 buf[150*100];
tgx::Image<tgx::RGB565> im(buf, 150, 100);
im.clear(tgx::RGB565_Black); // clear to full black
 
// JPEG decoder object from JPEGDEC library
JPEGDEC jpeg; 
 
// Load the jpeg image "batman" stored in RAM and link the decoder to TGX
// -> note that 'TGX_JPEGDraw' is passed as callback parameter.
jpeg.openRAM((uint8_t*)batman, sizeof(batman), TGX_JPEGDraw); 
 
// Draw the JPEG onto im at half scale, half opacity and upper left corner at pos (20, 10) inside im. 
im.JPEGDecode(png, {20, 10}, JPEG_SCALE_HALF, 0.5f);

Note

A complete example is available in the subfolder /examples/Teensy4/JPEG_test/.

Check the JPEGDEC documentation for additional details.

Drawing GIF images

Install Bitbank2's AnimatedGIF library from the Arduino library manager / platformio of directly from https://github.com/bitbank2/AnimatedGIF

Simply include both libraries into the project to activate the bindings between TGX and AnimatedGIF:

#include <tgx.h>
#include <AnimatedGIF.h>

Now, we can bind any AnimatedGIF decoder object to tgx images by providing it with the generic callback TGX_GIFDraw and then we can susequently decode GIFs using the Image::GIFplayFrame() method.

This method simply wraps around the playFrame() method fom the AnimateGIF library and can be called repeatedly to display successives frame in case of an animation.

Example:

// create a 150x100 image in RGB565 color format. 
tgx::RGB565 buf[150*100];
tgx::Image<tgx::RGB565> im(buf, 150, 100);
im.clear(tgx::RGB565_Black); // clear to full black
 
// GIF decoder object from AnimatedGIF library
AnimatedGIF gif;
 
// Load the GIF image "earth_128x128" stored in RAM and link the decoder to TGX
// -> note that 'TGX_GIFDraw' is passed as callback parameter.
gif.open((uint8_t*)earth_128x128, sizeof(earth_128x128), TGX_GIFDraw); 
 
// Draw the GIF onto im with upper left corner at pos (20, 10) inside im. 
im.GIFplayFrame(gif, { 20, 10 }); 
 
// we can call im.GIFplayFrame(gif, { 20, 10 }) again to draw the next frame if it is an animation... 

Note

A complete example is available in the subfolder /examples/Teensy4/GIF_test/.

Check the AnimatedGIf documentation for additional details.

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