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Re-enable line drawing path in render drivers

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This is still used for scaled line drawing in RenderDrawLinesWithRects()
This commit is contained in:
Sam Lantinga 2022-01-08 09:02:25 -08:00
parent dca281e810
commit 18e4d9fed1
7 changed files with 301 additions and 12 deletions
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91
src/render/opengles2/SDL_render_gles2.c
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@ -692,6 +692,63 @@ GLES2_QueueDrawPoints(SDL_Renderer * renderer, SDL_RenderCommand *cmd, const SDL
return 0;
}
static int
GLES2_QueueDrawLines(SDL_Renderer * renderer, SDL_RenderCommand *cmd, const SDL_FPoint * points, int count)
{
const SDL_bool colorswap = (renderer->target && (renderer->target->format == SDL_PIXELFORMAT_ARGB8888 || renderer->target->format == SDL_PIXELFORMAT_RGB888));
int i;
GLfloat prevx, prevy;
SDL_VertexSolid *verts = (SDL_VertexSolid *) SDL_AllocateRenderVertices(renderer, count * sizeof(*verts), 0, &cmd->data.draw.first);
SDL_Color color;
color.r = cmd->data.draw.r;
color.g = cmd->data.draw.g;
color.b = cmd->data.draw.b;
color.a = cmd->data.draw.a;
if (!verts) {
return -1;
}
if (colorswap) {
Uint8 r = color.r;
color.r = color.b;
color.b = r;
}
cmd->data.draw.count = count;
/* 0.5f offset to hit the center of the pixel. */
prevx = 0.5f + points->x;
prevy = 0.5f + points->y;
verts->position.x = prevx;
verts->position.y = prevy;
verts->color = color;
verts++;
/* bump the end of each line segment out a quarter of a pixel, to provoke
the diamond-exit rule. Without this, you won't just drop the last
pixel of the last line segment, but you might also drop pixels at the
edge of any given line segment along the way too. */
for (i = 1; i < count; i++) {
const GLfloat xstart = prevx;
const GLfloat ystart = prevy;
const GLfloat xend = points[i].x + 0.5f; /* 0.5f to hit pixel center. */
const GLfloat yend = points[i].y + 0.5f;
/* bump a little in the direction we are moving in. */
const GLfloat deltax = xend - xstart;
const GLfloat deltay = yend - ystart;
const GLfloat angle = SDL_atan2f(deltay, deltax);
prevx = xend + (SDL_cosf(angle) * 0.25f);
prevy = yend + (SDL_sinf(angle) * 0.25f);
verts->position.x = prevx;
verts->position.y = prevy;
verts->color = color;
verts++;
}
return 0;
}
static int
GLES2_QueueGeometry(SDL_Renderer *renderer, SDL_RenderCommand *cmd, SDL_Texture *texture,
const float *xy, int xy_stride, const SDL_Color *color, int color_stride, const float *uv, int uv_stride,
@ -1126,8 +1183,39 @@ GLES2_RunCommandQueue(SDL_Renderer * renderer, SDL_RenderCommand *cmd, void *ver
case SDL_RENDERCMD_COPY_EX: /* unused */
break;
case SDL_RENDERCMD_DRAW_LINES: /* unused */
case SDL_RENDERCMD_DRAW_LINES: {
if (SetDrawState(data, cmd, GLES2_IMAGESOURCE_SOLID) == 0) {
size_t count = cmd->data.draw.count;
if (count > 2) {
/* joined lines cannot be grouped */
data->glDrawArrays(GL_LINE_STRIP, 0, (GLsizei)count);
} else {
/* let's group non joined lines */
SDL_RenderCommand *finalcmd = cmd;
SDL_RenderCommand *nextcmd = cmd->next;
SDL_BlendMode thisblend = cmd->data.draw.blend;
while (nextcmd != NULL) {
const SDL_RenderCommandType nextcmdtype = nextcmd->command;
if (nextcmdtype != SDL_RENDERCMD_DRAW_LINES) {
break; /* can't go any further on this draw call, different render command up next. */
} else if (nextcmd->data.draw.count != 2) {
break; /* can't go any further on this draw call, those are joined lines */
} else if (nextcmd->data.draw.blend != thisblend) {
break; /* can't go any further on this draw call, different blendmode copy up next. */
} else {
finalcmd = nextcmd; /* we can combine copy operations here. Mark this one as the furthest okay command. */
count += cmd->data.draw.count;
}
nextcmd = nextcmd->next;
}
data->glDrawArrays(GL_LINES, 0, (GLsizei)count);
cmd = finalcmd; /* skip any copy commands we just combined in here. */
}
}
break;
}
case SDL_RENDERCMD_DRAW_POINTS:
case SDL_RENDERCMD_GEOMETRY: {
@ -2007,6 +2095,7 @@ GLES2_CreateRenderer(SDL_Window *window, Uint32 flags)
renderer->QueueSetViewport = GLES2_QueueSetViewport;
renderer->QueueSetDrawColor = GLES2_QueueSetViewport; /* SetViewport and SetDrawColor are (currently) no-ops. */
renderer->QueueDrawPoints = GLES2_QueueDrawPoints;
renderer->QueueDrawLines = GLES2_QueueDrawLines;
renderer->QueueGeometry = GLES2_QueueGeometry;
renderer->RunCommandQueue = GLES2_RunCommandQueue;
renderer->RenderReadPixels = GLES2_RenderReadPixels;