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REDESIGNED: DrawCircleSector()

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Ray 2019-03-28 18:53:41 +01:00
parent 186d34827a
commit 88dfd2ab23
2 changed files with 60 additions and 16 deletions
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2
src/raylib.h
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@ -1043,7 +1043,7 @@ RLAPI void DrawLineV(Vector2 startPos, Vector2 endPos, Color color);
RLAPI void DrawLineEx(Vector2 startPos, Vector2 endPos, float thick, Color color); // Draw a line defining thickness
RLAPI void DrawLineBezier(Vector2 startPos, Vector2 endPos, float thick, Color color); // Draw a line using cubic-bezier curves in-out
RLAPI void DrawCircle(int centerX, int centerY, float radius, Color color); // Draw a color-filled circle
RLAPI void DrawCircleSector(Vector2 center, float radius, int startAngle, int endAngle, Color color); // Draw a piece of a circle
RLAPI void DrawCircleSector(Vector2 center, float radius, int startAngle, int endAngle, int segments, Color color); // Draw a piece of a circle
RLAPI void DrawCircleGradient(int centerX, int centerY, float radius, Color color1, Color color2); // Draw a gradient-filled circle
RLAPI void DrawCircleV(Vector2 center, float radius, Color color); // Draw a color-filled circle (Vector version)
RLAPI void DrawCircleLines(int centerX, int centerY, float radius, Color color); // Draw circle outline

74
src/shapes.c
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@ -183,18 +183,40 @@ void DrawCircle(int centerX, int centerY, float radius, Color color)
}
// Draw a piece of a circle
// TODO: Support better angle resolution (now limited to CIRCLE_SECTOR_LENGTH)
void DrawCircleSector(Vector2 center, float radius, int startAngle, int endAngle, Color color)
void DrawCircleSector(Vector2 center, float radius, int startAngle, int endAngle, int segments, Color color)
{
#define CIRCLE_SECTOR_LENGTH 10
// Function expects (endAngle > startAngle)
if (endAngle < startAngle)
{
// Swap values
int tmp = startAngle;
startAngle = endAngle;
endAngle = tmp;
}
if (segments < 4)
{
// Calculate how many segments we need to draw a smooth circle, taken from https://stackoverflow.com/a/2244088
#define CIRCLE_ERROR_RATE 0.5f
// Calculate the maximum angle between segments based on the error rate.
float th = acosf(2*powf(1 - CIRCLE_ERROR_RATE/radius, 2) - 1);
segments = (endAngle - startAngle)*ceilf(2*PI/th)/360;
if (segments <= 0) segments = 4;
}
float stepLength = (float)(endAngle - startAngle)/(float)segments;
float angle = startAngle;
#if defined(SUPPORT_QUADS_DRAW_MODE)
if (rlCheckBufferLimit(4*((360/CIRCLE_SECTOR_LENGTH)/2))) rlglDraw();
if (rlCheckBufferLimit(4*segments/2)) rlglDraw();
rlEnableTexture(GetShapesTexture().id);
rlBegin(RL_QUADS);
for (int i = startAngle; i < endAngle; i += CIRCLE_SECTOR_LENGTH*2)
// NOTE: Every QUAD actually represents two segments
for (int i = 0; i < segments/2; i++)
{
rlColor4ub(color.r, color.g, color.b, color.a);
@ -202,28 +224,50 @@ void DrawCircleSector(Vector2 center, float radius, int startAngle, int endAngle
rlVertex2f(center.x, center.y);
rlTexCoord2f(recTexShapes.x/texShapes.width, (recTexShapes.y + recTexShapes.height)/texShapes.height);
rlVertex2f(center.x + sinf(DEG2RAD*i)*radius, center.y + cosf(DEG2RAD*i)*radius);
rlVertex2f(center.x + sinf(DEG2RAD*angle)*radius, center.y + cosf(DEG2RAD*angle)*radius);
rlTexCoord2f((recTexShapes.x + recTexShapes.width)/texShapes.width, (recTexShapes.y + recTexShapes.height)/texShapes.height);
rlVertex2f(center.x + sinf(DEG2RAD*(i + CIRCLE_SECTOR_LENGTH))*radius, center.y + cosf(DEG2RAD*(i + CIRCLE_SECTOR_LENGTH))*radius);
rlVertex2f(center.x + sinf(DEG2RAD*(angle + stepLength))*radius, center.y + cosf(DEG2RAD*(angle + stepLength))*radius);
rlTexCoord2f((recTexShapes.x + recTexShapes.width)/texShapes.width, recTexShapes.y/texShapes.height);
rlVertex2f(center.x + sinf(DEG2RAD*(i + CIRCLE_SECTOR_LENGTH*2))*radius, center.y + cosf(DEG2RAD*(i + CIRCLE_SECTOR_LENGTH*2))*radius);
rlVertex2f(center.x + sinf(DEG2RAD*(angle + stepLength*2))*radius, center.y + cosf(DEG2RAD*(angle + stepLength*2))*radius);
angle += (stepLength*2);
}
// NOTE: In case number of segments is odd, we add one last piece to the cake
if (segments%2)
{
rlColor4ub(color.r, color.g, color.b, color.a);
rlTexCoord2f(recTexShapes.x/texShapes.width, recTexShapes.y/texShapes.height);
rlVertex2f(center.x, center.y);
rlTexCoord2f(recTexShapes.x/texShapes.width, (recTexShapes.y + recTexShapes.height)/texShapes.height);
rlVertex2f(center.x + sinf(DEG2RAD*angle)*radius, center.y + cosf(DEG2RAD*angle)*radius);
rlTexCoord2f((recTexShapes.x + recTexShapes.width)/texShapes.width, (recTexShapes.y + recTexShapes.height)/texShapes.height);
rlVertex2f(center.x + sinf(DEG2RAD*(angle + stepLength))*radius, center.y + cosf(DEG2RAD*(angle + stepLength))*radius);
rlTexCoord2f((recTexShapes.x + recTexShapes.width)/texShapes.width, recTexShapes.y/texShapes.height);
rlVertex2f(center.x, center.y);
}
rlEnd();
rlDisableTexture();
#else
if (rlCheckBufferLimit(3*360/CIRCLE_SECTOR_LENGTH)) rlglDraw();
if (rlCheckBufferLimit(3*segments)) rlglDraw();
rlBegin(RL_TRIANGLES);
for (int i = startAngle; i < endAngle; i += CIRCLE_SECTOR_LENGTH)
for (int i = 0; i < segments; i++)
{
rlColor4ub(color.r, color.g, color.b, color.a);
rlVertex2f(center.x, center.y);
rlVertex2f(center.x + sinf(DEG2RAD*i)*radius, center.y + cosf(DEG2RAD*i)*radius);
rlVertex2f(center.x + sinf(DEG2RAD*(i + CIRCLE_SECTOR_LENGTH))*radius, center.y + cosf(DEG2RAD*(i + CIRCLE_SECTOR_LENGTH))*radius);
rlVertex2f(center.x + sinf(DEG2RAD*angle)*radius, center.y + cosf(DEG2RAD*angle)*radius);
rlVertex2f(center.x + sinf(DEG2RAD*(angle + stepLength))*radius, center.y + cosf(DEG2RAD*(angle + stepLength))*radius);
angle += stepLength;
}
rlEnd();
#endif
@ -252,7 +296,7 @@ void DrawCircleGradient(int centerX, int centerY, float radius, Color color1, Co
// NOTE: On OpenGL 3.3 and ES2 we use QUADS to avoid drawing order issues (view rlglDraw)
void DrawCircleV(Vector2 center, float radius, Color color)
{
DrawCircleSector(center, radius, 0, 360, color);
DrawCircleSector(center, radius, 0, 360, 36, color);
}
// Draw circle outline