From 7a49ce71a1e508eb59b296175731913192d0a24a Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Mon, 13 Oct 2025 14:34:24 -0700
Subject: [PATCH] Handle partial OpenGL shader availability
The pixelart shaders are not supported on OpenGL 2.1 (GLSL 130 isn't available)
Fixes the OpenGL renderer on macOS
---
src/render/opengl/SDL_render_gl.c | 49 +++++++++++++++++++++++++-----
src/render/opengl/SDL_shaders_gl.c | 36 ++++++++++++++++------
src/render/opengl/SDL_shaders_gl.h | 1 +
3 files changed, 69 insertions(+), 17 deletions(-)
diff --git a/src/render/opengl/SDL_render_gl.c b/src/render/opengl/SDL_render_gl.c
index 38d46b8c894ec..55aaca6a39558 100644
--- a/src/render/opengl/SDL_render_gl.c
+++ b/src/render/opengl/SDL_render_gl.c
@@ -91,6 +91,7 @@ typedef struct
bool debug_enabled;
bool GL_ARB_debug_output_supported;
+ bool pixelart_supported;
int errors;
char **error_messages;
GLDEBUGPROCARB next_error_callback;
@@ -455,7 +456,13 @@ static bool SetTextureScaleMode(GL_RenderData *data, GLenum textype, SDL_PixelFo
data->glTexParameteri(textype, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
data->glTexParameteri(textype, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
break;
- case SDL_SCALEMODE_PIXELART: // Uses linear sampling
+ case SDL_SCALEMODE_PIXELART: // Uses linear sampling if supported
+ if (!data->pixelart_supported) {
+ data->glTexParameteri(textype, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+ data->glTexParameteri(textype, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+ break;
+ }
+ SDL_FALLTHROUGH;
case SDL_SCALEMODE_LINEAR:
if (format == SDL_PIXELFORMAT_INDEX8) {
// We'll do linear sampling in the shader
@@ -1210,19 +1217,22 @@ static bool SetCopyState(GL_RenderData *data, const SDL_RenderCommand *cmd)
if (cmd->data.draw.texture_scale_mode == SDL_SCALEMODE_LINEAR) {
shader = SHADER_PALETTE_LINEAR;
shader_params = texturedata->texel_size;
- } else if (cmd->data.draw.texture_scale_mode == SDL_SCALEMODE_PIXELART) {
+ } else if (cmd->data.draw.texture_scale_mode == SDL_SCALEMODE_PIXELART &&
+ data->pixelart_supported) {
shader = SHADER_PALETTE_PIXELART;
shader_params = texturedata->texel_size;
}
break;
case SHADER_RGB:
- if (cmd->data.draw.texture_scale_mode == SDL_SCALEMODE_PIXELART) {
+ if (cmd->data.draw.texture_scale_mode == SDL_SCALEMODE_PIXELART &&
+ data->pixelart_supported) {
shader = SHADER_RGB_PIXELART;
shader_params = texturedata->texel_size;
}
break;
case SHADER_RGBA:
- if (cmd->data.draw.texture_scale_mode == SDL_SCALEMODE_PIXELART) {
+ if (cmd->data.draw.texture_scale_mode == SDL_SCALEMODE_PIXELART &&
+ data->pixelart_supported) {
shader = SHADER_RGBA_PIXELART;
shader_params = texturedata->texel_size;
}
@@ -1928,27 +1938,50 @@ static bool GL_CreateRenderer(SDL_Renderer *renderer, SDL_Window *window, SDL_Pr
data->shaders = GL_CreateShaderContext();
SDL_LogInfo(SDL_LOG_CATEGORY_RENDER, "OpenGL shaders: %s",
data->shaders ? "ENABLED" : "DISABLED");
- if (data->shaders) {
+ if (GL_SupportsShader(data->shaders, SHADER_RGB)) {
SDL_AddSupportedTextureFormat(renderer, SDL_PIXELFORMAT_RGBX32);
if (bgra_supported) {
SDL_AddSupportedTextureFormat(renderer, SDL_PIXELFORMAT_BGRX32);
}
+ } else {
+ SDL_LogInfo(SDL_LOG_CATEGORY_RENDER, "OpenGL RGB shaders not supported");
+ }
+ // We support PIXELART mode using a shader
+ if (GL_SupportsShader(data->shaders, SHADER_RGB_PIXELART) &&
+ GL_SupportsShader(data->shaders, SHADER_RGBA_PIXELART)) {
+ data->pixelart_supported = true;
+ } else {
+ SDL_LogInfo(SDL_LOG_CATEGORY_RENDER, "OpenGL PIXELART shaders not supported");
}
// We support INDEX8 textures using 2 textures and a shader
- if (data->shaders && data->num_texture_units >= 2) {
+ if (GL_SupportsShader(data->shaders, SHADER_PALETTE_NEAREST) &&
+ GL_SupportsShader(data->shaders, SHADER_PALETTE_LINEAR) &&
+ (!data->pixelart_supported || GL_SupportsShader(data->shaders, SHADER_PALETTE_PIXELART)) &&
+ data->num_texture_units >= 2) {
SDL_AddSupportedTextureFormat(renderer, SDL_PIXELFORMAT_INDEX8);
+ } else {
+ SDL_LogInfo(SDL_LOG_CATEGORY_RENDER, "OpenGL palette shaders not supported");
}
#ifdef SDL_HAVE_YUV
// We support YV12 textures using 3 textures and a shader
- if (data->shaders && data->num_texture_units >= 3) {
+ if (GL_SupportsShader(data->shaders, SHADER_YUV) &&
+ data->num_texture_units >= 3) {
SDL_AddSupportedTextureFormat(renderer, SDL_PIXELFORMAT_YV12);
SDL_AddSupportedTextureFormat(renderer, SDL_PIXELFORMAT_IYUV);
+ } else {
+ SDL_LogInfo(SDL_LOG_CATEGORY_RENDER, "OpenGL YUV not supported");
}
// We support NV12 textures using 2 textures and a shader
- if (data->shaders && data->num_texture_units >= 2) {
+ if (GL_SupportsShader(data->shaders, SHADER_NV12_RA) &&
+ GL_SupportsShader(data->shaders, SHADER_NV12_RG) &&
+ GL_SupportsShader(data->shaders, SHADER_NV21_RA) &&
+ GL_SupportsShader(data->shaders, SHADER_NV21_RG) &&
+ data->num_texture_units >= 2) {
SDL_AddSupportedTextureFormat(renderer, SDL_PIXELFORMAT_NV12);
SDL_AddSupportedTextureFormat(renderer, SDL_PIXELFORMAT_NV21);
+ } else {
+ SDL_LogInfo(SDL_LOG_CATEGORY_RENDER, "OpenGL NV12/NV21 not supported");
}
#endif
#ifdef SDL_PLATFORM_MACOS
diff --git a/src/render/opengl/SDL_shaders_gl.c b/src/render/opengl/SDL_shaders_gl.c
index 069123b24ed5f..164875127172e 100644
--- a/src/render/opengl/SDL_shaders_gl.c
+++ b/src/render/opengl/SDL_shaders_gl.c
@@ -520,10 +520,15 @@ static bool CompileShader(GL_ShaderContext *ctx, GLhandleARB shader, const char
info = SDL_small_alloc(char, length + 1, &isstack);
if (info) {
ctx->glGetInfoLogARB(shader, length, NULL, info);
- SDL_LogError(SDL_LOG_CATEGORY_RENDER, "Failed to compile shader:");
- SDL_LogError(SDL_LOG_CATEGORY_RENDER, "%s", defines);
- SDL_LogError(SDL_LOG_CATEGORY_RENDER, "%s", source);
- SDL_LogError(SDL_LOG_CATEGORY_RENDER, "%s", info);
+ SDL_LogDebug(SDL_LOG_CATEGORY_RENDER, "Failed to compile shader:");
+ if (version) {
+ SDL_LogDebug(SDL_LOG_CATEGORY_RENDER, "%s", version);
+ }
+ if (defines) {
+ SDL_LogDebug(SDL_LOG_CATEGORY_RENDER, "%s", defines);
+ }
+ SDL_LogDebug(SDL_LOG_CATEGORY_RENDER, "%s", source);
+ SDL_LogDebug(SDL_LOG_CATEGORY_RENDER, "%s", info);
SDL_small_free(info, isstack);
}
return false;
@@ -598,9 +603,18 @@ static bool CompileShaderProgram(GL_ShaderContext *ctx, int index, GL_ShaderData
static void DestroyShaderProgram(GL_ShaderContext *ctx, GL_ShaderData *data)
{
- ctx->glDeleteObjectARB(data->vert_shader);
- ctx->glDeleteObjectARB(data->frag_shader);
- ctx->glDeleteObjectARB(data->program);
+ if (data->vert_shader) {
+ ctx->glDeleteObjectARB(data->vert_shader);
+ data->vert_shader = 0;
+ }
+ if (data->frag_shader) {
+ ctx->glDeleteObjectARB(data->frag_shader);
+ data->frag_shader = 0;
+ }
+ if (data->program) {
+ ctx->glDeleteObjectARB(data->program);
+ data->program = 0;
+ }
}
GL_ShaderContext *GL_CreateShaderContext(void)
@@ -669,8 +683,7 @@ GL_ShaderContext *GL_CreateShaderContext(void)
// Compile all the shaders
for (i = 0; i < NUM_SHADERS; ++i) {
if (!CompileShaderProgram(ctx, i, &ctx->shaders[i])) {
- GL_DestroyShaderContext(ctx);
- return NULL;
+ DestroyShaderProgram(ctx, &ctx->shaders[i]);
}
}
@@ -678,6 +691,11 @@ GL_ShaderContext *GL_CreateShaderContext(void)
return ctx;
}
+bool GL_SupportsShader(GL_ShaderContext *ctx, GL_Shader shader)
+{
+ return ctx && ctx->shaders[shader].program;
+}
+
void GL_SelectShader(GL_ShaderContext *ctx, GL_Shader shader, const float *shader_params)
{
GLint location;
diff --git a/src/render/opengl/SDL_shaders_gl.h b/src/render/opengl/SDL_shaders_gl.h
index 350018b9a946e..438418472cbb7 100644
--- a/src/render/opengl/SDL_shaders_gl.h
+++ b/src/render/opengl/SDL_shaders_gl.h
@@ -51,6 +51,7 @@ typedef enum
typedef struct GL_ShaderContext GL_ShaderContext;
extern GL_ShaderContext *GL_CreateShaderContext(void);
+extern bool GL_SupportsShader(GL_ShaderContext *ctx, GL_Shader shader);
extern void GL_SelectShader(GL_ShaderContext *ctx, GL_Shader shader, const float *shader_params);
extern void GL_DestroyShaderContext(GL_ShaderContext *ctx);