1 files changed, 559 insertions, 0 deletions

diff --git a/contrib/SDL-3.2.8/test/testshader.c b/contrib/SDL-3.2.8/test/testshader.c
new file mode 100644
index 0000000..9b13890
--- /dev/null
+++ b/contrib/SDL-3.2.8/test/testshader.c
@@ -0,0 +1,559 @@
+/*
+  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely.
+*/
+/* This is a simple example of using GLSL shaders with SDL */
+
+#include <SDL3/SDL.h>
+#include <SDL3/SDL_main.h>
+#include <SDL3/SDL_test.h>
+
+#include "testutils.h"
+
+#include <stdlib.h>
+
+#ifdef HAVE_OPENGL
+
+#include <SDL3/SDL_opengl.h>
+
+static bool shaders_supported;
+static int current_shader = 0;
+
+enum
+{
+    SHADER_COLOR,
+    SHADER_TEXTURE,
+    SHADER_TEXCOORDS,
+    NUM_SHADERS
+};
+
+typedef struct
+{
+    GLhandleARB program;
+    GLhandleARB vert_shader;
+    GLhandleARB frag_shader;
+    const char *vert_source;
+    const char *frag_source;
+} ShaderData;
+
+static ShaderData shaders[NUM_SHADERS] = {
+
+    /* SHADER_COLOR */
+    { 0, 0, 0,
+      /* vertex shader */
+      "varying vec4 v_color;\n"
+      "\n"
+      "void main()\n"
+      "{\n"
+      "    gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;\n"
+      "    v_color = gl_Color;\n"
+      "}",
+      /* fragment shader */
+      "varying vec4 v_color;\n"
+      "\n"
+      "void main()\n"
+      "{\n"
+      "    gl_FragColor = v_color;\n"
+      "}" },
+
+    /* SHADER_TEXTURE */
+    { 0, 0, 0,
+      /* vertex shader */
+      "varying vec4 v_color;\n"
+      "varying vec2 v_texCoord;\n"
+      "\n"
+      "void main()\n"
+      "{\n"
+      "    gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;\n"
+      "    v_color = gl_Color;\n"
+      "    v_texCoord = vec2(gl_MultiTexCoord0);\n"
+      "}",
+      /* fragment shader */
+      "varying vec4 v_color;\n"
+      "varying vec2 v_texCoord;\n"
+      "uniform sampler2D tex0;\n"
+      "\n"
+      "void main()\n"
+      "{\n"
+      "    gl_FragColor = texture2D(tex0, v_texCoord) * v_color;\n"
+      "}" },
+
+    /* SHADER_TEXCOORDS */
+    { 0, 0, 0,
+      /* vertex shader */
+      "varying vec2 v_texCoord;\n"
+      "\n"
+      "void main()\n"
+      "{\n"
+      "    gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;\n"
+      "    v_texCoord = vec2(gl_MultiTexCoord0);\n"
+      "}",
+      /* fragment shader */
+      "varying vec2 v_texCoord;\n"
+      "\n"
+      "void main()\n"
+      "{\n"
+      "    vec4 color;\n"
+      "    vec2 delta;\n"
+      "    float dist;\n"
+      "\n"
+      "    delta = vec2(0.5, 0.5) - v_texCoord;\n"
+      "    dist = dot(delta, delta);\n"
+      "\n"
+      "    color.r = v_texCoord.x;\n"
+      "    color.g = v_texCoord.x * v_texCoord.y;\n"
+      "    color.b = v_texCoord.y;\n"
+      "    color.a = 1.0 - (dist * 4.0);\n"
+      "    gl_FragColor = color;\n"
+      "}" },
+};
+
+static PFNGLATTACHOBJECTARBPROC pglAttachObjectARB;
+static PFNGLCOMPILESHADERARBPROC pglCompileShaderARB;
+static PFNGLCREATEPROGRAMOBJECTARBPROC pglCreateProgramObjectARB;
+static PFNGLCREATESHADEROBJECTARBPROC pglCreateShaderObjectARB;
+static PFNGLDELETEOBJECTARBPROC pglDeleteObjectARB;
+static PFNGLGETINFOLOGARBPROC pglGetInfoLogARB;
+static PFNGLGETOBJECTPARAMETERIVARBPROC pglGetObjectParameterivARB;
+static PFNGLGETUNIFORMLOCATIONARBPROC pglGetUniformLocationARB;
+static PFNGLLINKPROGRAMARBPROC pglLinkProgramARB;
+static PFNGLSHADERSOURCEARBPROC pglShaderSourceARB;
+static PFNGLUNIFORM1IARBPROC pglUniform1iARB;
+static PFNGLUSEPROGRAMOBJECTARBPROC pglUseProgramObjectARB;
+
+static bool CompileShader(GLhandleARB shader, const char *source)
+{
+    GLint status = 0;
+
+    pglShaderSourceARB(shader, 1, &source, NULL);
+    pglCompileShaderARB(shader);
+    pglGetObjectParameterivARB(shader, GL_OBJECT_COMPILE_STATUS_ARB, &status);
+    if (status == 0) {
+        GLint length = 0;
+        char *info;
+
+        pglGetObjectParameterivARB(shader, GL_OBJECT_INFO_LOG_LENGTH_ARB, &length);
+        info = (char *)SDL_malloc((size_t)length + 1);
+        if (!info) {
+            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Out of memory!");
+        } else {
+            pglGetInfoLogARB(shader, length, NULL, info);
+            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Failed to compile shader:");
+            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "%s", source);
+            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "%s", info);
+            SDL_free(info);
+        }
+        return false;
+    } else {
+        return true;
+    }
+}
+
+static bool LinkProgram(ShaderData *data)
+{
+    GLint status = 0;
+
+    pglAttachObjectARB(data->program, data->vert_shader);
+    pglAttachObjectARB(data->program, data->frag_shader);
+    pglLinkProgramARB(data->program);
+
+    pglGetObjectParameterivARB(data->program, GL_OBJECT_LINK_STATUS_ARB, &status);
+    if (status == 0) {
+        GLint length = 0;
+        char *info;
+
+        pglGetObjectParameterivARB(data->program, GL_OBJECT_INFO_LOG_LENGTH_ARB, &length);
+        info = (char *)SDL_malloc((size_t)length + 1);
+        if (!info) {
+            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Out of memory!");
+        } else {
+            pglGetInfoLogARB(data->program, length, NULL, info);
+            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Failed to link program:");
+            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "%s", info);
+            SDL_free(info);
+        }
+        return false;
+    } else {
+        return true;
+    }
+}
+
+static bool CompileShaderProgram(ShaderData *data)
+{
+    const int num_tmus_bound = 4;
+    int i;
+    GLint location;
+
+    glGetError();
+
+    /* Create one program object to rule them all */
+    data->program = pglCreateProgramObjectARB();
+
+    /* Create the vertex shader */
+    data->vert_shader = pglCreateShaderObjectARB(GL_VERTEX_SHADER_ARB);
+    if (!CompileShader(data->vert_shader, data->vert_source)) {
+        return false;
+    }
+
+    /* Create the fragment shader */
+    data->frag_shader = pglCreateShaderObjectARB(GL_FRAGMENT_SHADER_ARB);
+    if (!CompileShader(data->frag_shader, data->frag_source)) {
+        return false;
+    }
+
+    /* ... and in the darkness bind them */
+    if (!LinkProgram(data)) {
+        return false;
+    }
+
+    /* Set up some uniform variables */
+    pglUseProgramObjectARB(data->program);
+    for (i = 0; i < num_tmus_bound; ++i) {
+        char tex_name[5];
+        (void)SDL_snprintf(tex_name, SDL_arraysize(tex_name), "tex%d", i);
+        location = pglGetUniformLocationARB(data->program, tex_name);
+        if (location >= 0) {
+            pglUniform1iARB(location, i);
+        }
+    }
+    pglUseProgramObjectARB(0);
+
+    return (glGetError() == GL_NO_ERROR);
+}
+
+static void DestroyShaderProgram(ShaderData *data)
+{
+    if (shaders_supported) {
+        pglDeleteObjectARB(data->vert_shader);
+        pglDeleteObjectARB(data->frag_shader);
+        pglDeleteObjectARB(data->program);
+    }
+}
+
+static bool InitShaders(void)
+{
+    int i;
+
+    /* Check for shader support */
+    shaders_supported = false;
+    if (SDL_GL_ExtensionSupported("GL_ARB_shader_objects") &&
+        SDL_GL_ExtensionSupported("GL_ARB_shading_language_100") &&
+        SDL_GL_ExtensionSupported("GL_ARB_vertex_shader") &&
+        SDL_GL_ExtensionSupported("GL_ARB_fragment_shader")) {
+        pglAttachObjectARB = (PFNGLATTACHOBJECTARBPROC)SDL_GL_GetProcAddress("glAttachObjectARB");
+        pglCompileShaderARB = (PFNGLCOMPILESHADERARBPROC)SDL_GL_GetProcAddress("glCompileShaderARB");
+        pglCreateProgramObjectARB = (PFNGLCREATEPROGRAMOBJECTARBPROC)SDL_GL_GetProcAddress("glCreateProgramObjectARB");
+        pglCreateShaderObjectARB = (PFNGLCREATESHADEROBJECTARBPROC)SDL_GL_GetProcAddress("glCreateShaderObjectARB");
+        pglDeleteObjectARB = (PFNGLDELETEOBJECTARBPROC)SDL_GL_GetProcAddress("glDeleteObjectARB");
+        pglGetInfoLogARB = (PFNGLGETINFOLOGARBPROC)SDL_GL_GetProcAddress("glGetInfoLogARB");
+        pglGetObjectParameterivARB = (PFNGLGETOBJECTPARAMETERIVARBPROC)SDL_GL_GetProcAddress("glGetObjectParameterivARB");
+        pglGetUniformLocationARB = (PFNGLGETUNIFORMLOCATIONARBPROC)SDL_GL_GetProcAddress("glGetUniformLocationARB");
+        pglLinkProgramARB = (PFNGLLINKPROGRAMARBPROC)SDL_GL_GetProcAddress("glLinkProgramARB");
+        pglShaderSourceARB = (PFNGLSHADERSOURCEARBPROC)SDL_GL_GetProcAddress("glShaderSourceARB");
+        pglUniform1iARB = (PFNGLUNIFORM1IARBPROC)SDL_GL_GetProcAddress("glUniform1iARB");
+        pglUseProgramObjectARB = (PFNGLUSEPROGRAMOBJECTARBPROC)SDL_GL_GetProcAddress("glUseProgramObjectARB");
+        if (pglAttachObjectARB &&
+            pglCompileShaderARB &&
+            pglCreateProgramObjectARB &&
+            pglCreateShaderObjectARB &&
+            pglDeleteObjectARB &&
+            pglGetInfoLogARB &&
+            pglGetObjectParameterivARB &&
+            pglGetUniformLocationARB &&
+            pglLinkProgramARB &&
+            pglShaderSourceARB &&
+            pglUniform1iARB &&
+            pglUseProgramObjectARB) {
+            shaders_supported = true;
+        }
+    }
+
+    if (!shaders_supported) {
+        return false;
+    }
+
+    /* Compile all the shaders */
+    for (i = 0; i < NUM_SHADERS; ++i) {
+        if (!CompileShaderProgram(&shaders[i])) {
+            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Unable to compile shader!");
+            return false;
+        }
+    }
+
+    /* We're done! */
+    return true;
+}
+
+static void QuitShaders(void)
+{
+    int i;
+
+    for (i = 0; i < NUM_SHADERS; ++i) {
+        DestroyShaderProgram(&shaders[i]);
+    }
+}
+
+/* Quick utility function for texture creation */
+static int
+power_of_two(int input)
+{
+    int value = 1;
+
+    while (value < input) {
+        value <<= 1;
+    }
+    return value;
+}
+
+static GLuint
+SDL_GL_LoadTexture(SDL_Surface *surface, GLfloat *texcoord)
+{
+    GLuint texture;
+    int w, h;
+    SDL_Surface *image;
+    SDL_Rect area;
+    SDL_BlendMode saved_mode;
+
+    /* Use the surface width and height expanded to powers of 2 */
+    w = power_of_two(surface->w);
+    h = power_of_two(surface->h);
+    texcoord[0] = 0.0f;                    /* Min X */
+    texcoord[1] = 0.0f;                    /* Min Y */
+    texcoord[2] = (GLfloat)surface->w / w; /* Max X */
+    texcoord[3] = (GLfloat)surface->h / h; /* Max Y */
+
+    image = SDL_CreateSurface(w, h, SDL_PIXELFORMAT_RGBA32);
+    if (!image) {
+        return 0;
+    }
+
+    /* Save the alpha blending attributes */
+    SDL_GetSurfaceBlendMode(surface, &saved_mode);
+    SDL_SetSurfaceBlendMode(surface, SDL_BLENDMODE_NONE);
+
+    /* Copy the surface into the GL texture image */
+    area.x = 0;
+    area.y = 0;
+    area.w = surface->w;
+    area.h = surface->h;
+    SDL_BlitSurface(surface, &area, image, &area);
+
+    /* Restore the alpha blending attributes */
+    SDL_SetSurfaceBlendMode(surface, saved_mode);
+
+    /* Create an OpenGL texture for the image */
+    glGenTextures(1, &texture);
+    glBindTexture(GL_TEXTURE_2D, texture);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+    glTexImage2D(GL_TEXTURE_2D,
+                 0,
+                 GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, image->pixels);
+    SDL_DestroySurface(image); /* No longer needed */
+
+    return texture;
+}
+
+/* A general OpenGL initialization function.    Sets all of the initial parameters. */
+static void InitGL(int Width, int Height) /* We call this right after our OpenGL window is created. */
+{
+    GLdouble aspect;
+
+    glViewport(0, 0, Width, Height);
+    glClearColor(0.0f, 0.0f, 0.0f, 0.0f); /* This Will Clear The Background Color To Black */
+    glClearDepth(1.0);                    /* Enables Clearing Of The Depth Buffer */
+    glDepthFunc(GL_LESS);                 /* The Type Of Depth Test To Do */
+    glEnable(GL_DEPTH_TEST);              /* Enables Depth Testing */
+    glShadeModel(GL_SMOOTH);              /* Enables Smooth Color Shading */
+
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity(); /* Reset The Projection Matrix */
+
+    aspect = (GLdouble)Width / Height;
+    glOrtho(-3.0, 3.0, -3.0 / aspect, 3.0 / aspect, 0.0, 1.0);
+
+    glMatrixMode(GL_MODELVIEW);
+}
+
+/* The main drawing function. */
+static void DrawGLScene(SDL_Window *window, GLuint texture, GLfloat *texcoord)
+{
+    /* Texture coordinate lookup, to make it simple */
+    enum
+    {
+        MINX,
+        MINY,
+        MAXX,
+        MAXY
+    };
+
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); /* Clear The Screen And The Depth Buffer */
+    glLoadIdentity();                                   /* Reset The View */
+
+    glTranslatef(-1.5f, 0.0f, 0.0f); /* Move Left 1.5 Units */
+
+    /* draw a triangle (in smooth coloring mode) */
+    glBegin(GL_POLYGON);            /* start drawing a polygon */
+    glColor3f(1.0f, 0.0f, 0.0f);    /* Set The Color To Red */
+    glVertex3f(0.0f, 1.0f, 0.0f);   /* Top */
+    glColor3f(0.0f, 1.0f, 0.0f);    /* Set The Color To Green */
+    glVertex3f(1.0f, -1.0f, 0.0f);  /* Bottom Right */
+    glColor3f(0.0f, 0.0f, 1.0f);    /* Set The Color To Blue */
+    glVertex3f(-1.0f, -1.0f, 0.0f); /* Bottom Left */
+    glEnd();                        /* we're done with the polygon (smooth color interpolation) */
+
+    glTranslatef(3.0f, 0.0f, 0.0f); /* Move Right 3 Units */
+
+    /* Enable blending */
+    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+    glEnable(GL_BLEND);
+    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
+    /* draw a textured square (quadrilateral) */
+    glEnable(GL_TEXTURE_2D);
+    glBindTexture(GL_TEXTURE_2D, texture);
+    glColor3f(1.0f, 1.0f, 1.0f);
+    if (shaders_supported) {
+        pglUseProgramObjectARB(shaders[current_shader].program);
+    }
+
+    glBegin(GL_QUADS); /* start drawing a polygon (4 sided) */
+    glTexCoord2f(texcoord[MINX], texcoord[MINY]);
+    glVertex3f(-1.0f, 1.0f, 0.0f); /* Top Left */
+    glTexCoord2f(texcoord[MAXX], texcoord[MINY]);
+    glVertex3f(1.0f, 1.0f, 0.0f); /* Top Right */
+    glTexCoord2f(texcoord[MAXX], texcoord[MAXY]);
+    glVertex3f(1.0f, -1.0f, 0.0f); /* Bottom Right */
+    glTexCoord2f(texcoord[MINX], texcoord[MAXY]);
+    glVertex3f(-1.0f, -1.0f, 0.0f); /* Bottom Left */
+    glEnd();                        /* done with the polygon */
+
+    if (shaders_supported) {
+        pglUseProgramObjectARB(0);
+    }
+    glDisable(GL_TEXTURE_2D);
+
+    /* swap buffers to display, since we're double buffered. */
+    SDL_GL_SwapWindow(window);
+}
+
+int main(int argc, char **argv)
+{
+    int i;
+    int done;
+    SDL_Window *window;
+    char *filename = NULL;
+    SDL_Surface *surface;
+    GLuint texture;
+    GLfloat texcoords[4];
+    SDLTest_CommonState *state;
+
+    /* Initialize test framework */
+    state = SDLTest_CommonCreateState(argv, 0);
+    if (!state) {
+        return 1;
+    }
+
+    /* Parse commandline */
+    for (i = 1; i < argc;) {
+        int consumed;
+
+        consumed = SDLTest_CommonArg(state, i);
+        if (!consumed) {
+            if (!filename) {
+                filename = argv[i];
+                consumed = 1;
+            }
+        }
+        if (consumed <= 0) {
+            static const char *options[] = { "[icon.bmp]", NULL };
+            SDLTest_CommonLogUsage(state, argv[0], options);
+            exit(1);
+        }
+
+        i += consumed;
+    }
+
+    /* Initialize SDL for video output */
+    if (!SDL_Init(SDL_INIT_VIDEO)) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Unable to initialize SDL: %s", SDL_GetError());
+        exit(1);
+    }
+
+    /* Create a 640x480 OpenGL screen */
+    window = SDL_CreateWindow("Shader Demo", 640, 480, SDL_WINDOW_OPENGL);
+    if (!window) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Unable to create OpenGL window: %s", SDL_GetError());
+        SDL_Quit();
+        exit(2);
+    }
+
+    if (!SDL_GL_CreateContext(window)) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Unable to create OpenGL context: %s", SDL_GetError());
+        SDL_Quit();
+        exit(2);
+    }
+
+    filename = GetResourceFilename(NULL, "icon.bmp");
+    surface = SDL_LoadBMP(filename);
+    SDL_free(filename);
+
+    if (!surface) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Unable to load icon.bmp: %s", SDL_GetError());
+        SDL_Quit();
+        exit(3);
+    }
+    texture = SDL_GL_LoadTexture(surface, texcoords);
+    SDL_DestroySurface(surface);
+
+    /* Loop, drawing and checking events */
+    InitGL(640, 480);
+    if (InitShaders()) {
+        SDL_Log("Shaders supported, press SPACE to cycle them.");
+    } else {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Shaders not supported!");
+    }
+    done = 0;
+    while (!done) {
+        DrawGLScene(window, texture, texcoords);
+
+        /* This could go in a separate function */
+        {
+            SDL_Event event;
+            while (SDL_PollEvent(&event)) {
+                if (event.type == SDL_EVENT_QUIT) {
+                    done = 1;
+                }
+                if (event.type == SDL_EVENT_KEY_DOWN) {
+                    if (event.key.key == SDLK_SPACE) {
+                        current_shader = (current_shader + 1) % NUM_SHADERS;
+                    }
+                    if (event.key.key == SDLK_ESCAPE) {
+                        done = 1;
+                    }
+                }
+            }
+        }
+    }
+    QuitShaders();
+    SDL_Quit();
+    SDLTest_CommonDestroyState(state);
+    return 1;
+}
+
+#else /* HAVE_OPENGL */
+
+int main(int argc, char *argv[])
+{
+    SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "No OpenGL support on this system");
+    return 1;
+}
+
+#endif /* HAVE_OPENGL */