Added an HDR gradient test to testcolorspace

main
Sam Lantinga 2024-02-01 14:21:32 -08:00
parent dc607c666b
commit ea0853d23d
1 changed files with 173 additions and 1 deletions

View File

@ -32,7 +32,7 @@ static SDL_Colorspace colorspace = SDL_COLORSPACE_SRGB;
static const char *colorspace_name = "sRGB";
static int renderer_count = 0;
static int renderer_index = 0;
static int stage_count = 4;
static int stage_count = 6;
static int stage_index = 0;
static int done;
@ -144,6 +144,20 @@ static void DrawText(float x, float y, const char *fmt, ...)
SDL_free(text);
}
static void DrawTextWhite(float x, float y, const char *fmt, ...)
{
char *text;
va_list ap;
va_start(ap, fmt);
SDL_vasprintf(&text, fmt, ap);
va_end(ap);
SDL_SetRenderDrawColor(renderer, 255, 255, 255, 255);
SDLTest_DrawString(renderer, x, y, text);
SDL_free(text);
}
static void RenderClearBackground(void)
{
/* Draw a 50% gray background.
@ -316,6 +330,158 @@ static void RenderBlendTexture(void)
SDL_DestroyTexture(b);
}
static void DrawGradient(float x, float y, float width, float height, float start, float end)
{
float xy[8];
const int xy_stride = 2 * sizeof(float);
SDL_FColor color[4];
const int color_stride = sizeof(SDL_FColor);
const int num_vertices = 4;
const int indices[6] = { 0, 1, 2, 0, 2, 3 };
const int num_indices = 6;
const int size_indices = 4;
float minx, miny, maxx, maxy;
SDL_FColor min_color = { start, start, start, 1.0f };
SDL_FColor max_color = { end, end, end, 1.0f };
minx = x;
miny = y;
maxx = minx + width;
maxy = miny + height;
xy[0] = minx;
xy[1] = miny;
xy[2] = maxx;
xy[3] = miny;
xy[4] = maxx;
xy[5] = maxy;
xy[6] = minx;
xy[7] = maxy;
color[0] = min_color;
color[1] = max_color;
color[2] = max_color;
color[3] = min_color;
SDL_RenderGeometryRaw(renderer, NULL, xy, xy_stride, color, color_stride, NULL, 0, num_vertices, indices, num_indices, size_indices);
}
static void RenderGradientDrawing(void)
{
SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
SDL_RenderClear(renderer);
float x = TEXT_START_X;
float y = TEXT_START_Y;
DrawTextWhite(x, y, "%s %s", renderer_name, colorspace_name);
y += TEXT_LINE_ADVANCE;
DrawTextWhite(x, y, "Test: Draw SDR and HDR gradients");
y += TEXT_LINE_ADVANCE;
y += TEXT_LINE_ADVANCE;
DrawTextWhite(x, y, "SDR mathematically linear gradient (%d nits)", 80);
y += TEXT_LINE_ADVANCE;
DrawGradient(x, y, WINDOW_WIDTH - 2 * x, 64.0f, 0.0f, 1.0f);
y += 64.0f;
y += TEXT_LINE_ADVANCE;
y += TEXT_LINE_ADVANCE;
DrawTextWhite(x, y, "HDR mathematically linear gradient (%d nits)", 400);
y += TEXT_LINE_ADVANCE;
SDL_SetRenderDrawColorspace(renderer, SDL_COLORSPACE_SCRGB);
DrawGradient(x, y, WINDOW_WIDTH - 2 * x, 64.0f, 0.0f, 5.0f);
SDL_SetRenderDrawColorspace(renderer, SDL_COLORSPACE_SRGB);
y += 64.0f;
y += TEXT_LINE_ADVANCE;
y += TEXT_LINE_ADVANCE;
DrawTextWhite(x, y, "HDR mathematically linear gradient (%d nits)", 1000);
y += TEXT_LINE_ADVANCE;
SDL_SetRenderDrawColorspace(renderer, SDL_COLORSPACE_SCRGB);
DrawGradient(x, y, WINDOW_WIDTH - 2 * x, 64.0f, 0.0f, 12.5f);
SDL_SetRenderDrawColorspace(renderer, SDL_COLORSPACE_SRGB);
y += 64.0f;
}
static SDL_Texture *CreateGradientTexture(int width, float start, float end)
{
SDL_Texture *texture;
float *pixels;
texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_RGBA128_FLOAT, SDL_TEXTUREACCESS_STATIC, width, 1);
if (!texture) {
return NULL;
}
pixels = (float *)SDL_malloc(width * sizeof(float) * 4);
if (pixels) {
int i;
float length = (end - start);
for (i = 0; i < width; ++i) {
/* Use a 2.4 gamma function to create a perceptually linear gradient */
float v = SDL_powf(start + (length * i) / width, 2.4f);
pixels[i * 4 + 0] = v;
pixels[i * 4 + 1] = v;
pixels[i * 4 + 2] = v;
pixels[i * 4 + 3] = 1.0f;
}
SDL_UpdateTexture(texture, NULL, pixels, width * sizeof(float) * 4);
SDL_free(pixels);
}
return texture;
}
static void DrawGradientTexture(float x, float y, float width, float height, float start, float end)
{
SDL_FRect rect = { x, y, width, height };
SDL_Texture *texture = CreateGradientTexture((int)width, start, end);
SDL_RenderTexture(renderer, texture, NULL, &rect);
SDL_DestroyTexture(texture);
}
static void RenderGradientTexture(void)
{
SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
SDL_RenderClear(renderer);
float x = TEXT_START_X;
float y = TEXT_START_Y;
DrawTextWhite(x, y, "%s %s", renderer_name, colorspace_name);
y += TEXT_LINE_ADVANCE;
DrawTextWhite(x, y, "Test: Draw SDR and HDR gradients");
y += TEXT_LINE_ADVANCE;
y += TEXT_LINE_ADVANCE;
DrawTextWhite(x, y, "SDR perceptually linear gradient (%d nits)", 80);
y += TEXT_LINE_ADVANCE;
DrawGradientTexture(x, y, WINDOW_WIDTH - 2 * x, 64.0f, 0.0f, 1.0f);
y += 64.0f;
y += TEXT_LINE_ADVANCE;
y += TEXT_LINE_ADVANCE;
DrawTextWhite(x, y, "HDR perceptually linear gradient (%d nits)", 400);
y += TEXT_LINE_ADVANCE;
DrawGradientTexture(x, y, WINDOW_WIDTH - 2 * x, 64.0f, 0.0f, 5.0f);
y += 64.0f;
y += TEXT_LINE_ADVANCE;
y += TEXT_LINE_ADVANCE;
DrawTextWhite(x, y, "HDR perceptually linear gradient (%d nits)", 1000);
y += TEXT_LINE_ADVANCE;
DrawGradientTexture(x, y, WINDOW_WIDTH - 2 * x, 64.0f, 0.0f, 12.5f);
y += 64.0f;
}
static void loop(void)
{
SDL_Event event;
@ -364,6 +530,12 @@ static void loop(void)
case 3:
RenderBlendTexture();
break;
case 4:
RenderGradientDrawing();
break;
case 5:
RenderGradientTexture();
break;
}
SDL_RenderPresent(renderer);