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love.graphics.arc is now better and actually draws in the right direction

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Bill Meltsner
2011-12-22 03:37:34 -06:00
parent 7378a90101
commit bc278cf2b8
2 changed files with 39 additions and 29 deletions
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src/modules/graphics/opengl/Graphics.cpp
+29 -25
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@@ -834,44 +834,48 @@ namespace opengl
void Graphics::arc(DrawMode mode, float x, float y, float radius, float angle1, float angle2, int points)
{
angle1 = fmod(angle1, 2.0f * (float)LOVE_M_PI);
angle2 = fmod(angle2, 2.0f * (float)LOVE_M_PI);
if (angle1 == angle2)
// Nothing to display with no points or equal angles. (Or is there with line mode?)
if (points <= 0 || angle1 == angle2)
return;
else if (angle1 > angle2)
angle2 += (float)LOVE_M_PI * 2.0f;
// Oh, you want to draw a circle?
if (fabs(angle1 - angle2) >= 2.0f * (float) LOVE_M_PI)
{
circle(mode, x, y, radius, points);
return;
}
float angle_shift = (angle2 - angle1) / points;
// Bail on precision issues.
if (angle_shift == 0.0)
return;
if (points <= 0) points = 1;
float angle_shift = ((angle2 - angle1) / points);
float phi = angle1;
int num_coords = (points + 3) * 2;
float * coords = new float[num_coords];
coords[0] = coords[num_coords - 2] = x;
coords[1] = coords[num_coords - 1] = y;
for (int i = 0; i <= points; ++i, phi += angle_shift)
{
coords[2 * (i+1)] = x + radius * cos(phi);
coords[2 * (i+1) + 1] = y + radius * sin(phi);
}
// GL_POLYGON can only fill-draw convex polygons, so we need to do stuff manually here
if (mode == DRAW_LINE)
{
float *coords = new float[(points + 3) * 2];
coords[0] = coords[2 * points + 4] = x;
coords[1] = coords[2 * points + 5] = y;
for (int i = 0; i <= points; ++i, phi += angle_shift)
{
coords[2 * (i+1)] = x + radius * cos(phi);
coords[2 * (i+1) + 1] = y - radius * sin(phi);
}
polyline(coords, (points + 3) * 2); // artifacts at sharp angles if set to looping
delete[] coords;
}
polyline(coords, num_coords); // Artifacts at sharp angles if set to looping.
else
{
glDisable(GL_TEXTURE_2D);
glBegin(GL_TRIANGLE_FAN);
glVertex2f(x, y);
for (int i = 0; i <= points; ++i, phi += angle_shift)
glVertex2f(x + radius * cos(phi), y - radius * sin(phi));
glEnd();
glEnableClientState(GL_VERTEX_ARRAY);
glVertexPointer(2, GL_FLOAT, 0, (const GLvoid *) coords);
glDrawArrays(GL_TRIANGLE_FAN, 0, points + 2);
glDisableClientState(GL_VERTEX_ARRAY);
glEnable(GL_TEXTURE_2D);
}
delete[] coords;
}
/// @param mode the draw mode
src/modules/graphics/opengl/wrap_Graphics.cpp
+10 -4
View File
@@ -1018,10 +1018,11 @@ namespace opengl
float y = (float)luaL_checknumber(L, 3);
float radius = (float)luaL_checknumber(L, 4);
int points;
if (lua_gettop(L) > 4)
points = lua_tointeger(L, 5);
else
if (lua_isnoneornil(L, 5))
points = radius > 10 ? radius : 10;
else
points = luaL_checkint(L, 5);
instance->circle(mode, x, y, radius, points);
return 0;
}
@@ -1038,7 +1039,12 @@ namespace opengl
float radius = (float)luaL_checknumber(L, 4);
float angle1 = (float)luaL_checknumber(L, 5);
float angle2 = (float)luaL_checknumber(L, 6);
int points = luaL_optint(L, 7, 10);
int points;
if (lua_isnoneornil(L, 7))
points = radius > 10 ? radius : 10;
else
points = luaL_checkint(L, 7);
instance->arc(mode, x, y, radius, angle1, angle2, points);
return 0;
}