Set up a multipass shader

CMakeLists.txt

@@ -49,6 +49,10 @@ elseif(TARGET_TYPE STREQUAL game)
     ${ASSETS_SOURCE_DIR}/shared/shaders/textured.vert shaders/textured.vert
     ${ASSETS_SOURCE_DIR}/shared/shaders/textured.frag shaders/textured.frag
   )
+  tool_copy(shader_test
+    ${ASSETS_SOURCE_DIR}/shared/shaders/test.vert shaders/test.vert
+    ${ASSETS_SOURCE_DIR}/shared/shaders/test.frag shaders/test.frag
+  )
 
   # Fonts
   tool_copy(font_opensans
@@ -143,6 +147,7 @@ elseif(TARGET_TYPE STREQUAL game)
       vn_sammy
 
       shader_textured
+      shader_test
       font_opensans
       texture_test
     )

src/display/shader/shader.c

@@ -10,11 +10,10 @@
 void shaderInit(shader_t *shader,
   char *vertexShaderSource, char* fragmentShaderSource
 ) {
-  int32_t isSuccess, maxLength, i;
+  int32_t isSuccess, maxLength, i, texture;
   char *error;
   GLuint shaderVertex, shaderFragment, shaderProgram;
   GLint size; // size of the variable
-  GLenum type; // type of the variable (float, vec3 or mat4, etc)
   GLsizei length; // name length
 
   GLchar const* filesVertex[] = { vertexShaderSource };
@@ -77,14 +76,19 @@ void shaderInit(shader_t *shader,
   // Extract uniforms
   glGetProgramiv(shaderProgram, GL_ACTIVE_UNIFORMS, &shader->uniformCount);
 
+  texture = 0;
   for(i = 0; i < shader->uniformCount; i++) {
-    shader->uniforms[i] = shader->uniformBuffer + (i * SHADER_UNIFORM_NAME_MAX);
+    shader->uniformNames[i] = (
+      shader->uniformBuffer + (i * SHADER_UNIFORM_NAME_MAX)
+    );
+
     glGetActiveUniform(
       shaderProgram, (GLuint)i, SHADER_UNIFORM_NAME_MAX,
-      &length, &size, &type, shader->uniforms[i]
+      &length, &size, shader->types + i, shader->uniformNames[i]
     );
     
     // TODO: Reset uniforms to zero.
+    if(shader->types[i] == GL_SAMPLER_2D) shader->textureSlots[i] = texture++;
   }
 
   // Bind the shader
@@ -94,7 +98,7 @@ void shaderInit(shader_t *shader,
 shaderuniform_t shaderGetUniform(shader_t *shader, char *name) {
   int32_t i;
   for(i = 0; i < shader->uniformCount; i++) {
-    if(strcmp(shader->uniforms[i], name) == 0) return i;
+    if(strcmp(shader->uniformNames[i], name) == 0) return i;
   }
   return (shaderuniform_t)-1;
 }
@@ -112,8 +116,8 @@ void shaderUse(shader_t *shader) {
 void shaderUseTexture(
   shader_t *shader, shaderuniform_t uniform, texture_t *texture
 ) {
+  int32_t i = shader->textureSlots[(int32_t)uniform];
   // TODO: I need to be able to get the texture ID
-  int32_t i = 0;
   glActiveTexture(GL_TEXTURE0 + i);
   glBindTexture(GL_TEXTURE_2D, texture->id);
   glUniform1i(uniform, i);

src/display/shader/shader.h

@@ -13,7 +13,7 @@
 #include "../../util/array.h"
 
 #define SHADER_UNIFORM_NAME_MAX 24
-#define SHADER_UNIFORM_COUNT 8
+#define SHADER_UNIFORM_COUNT 16
 
 /** Representation of a shader uniform */
 typedef GLuint shaderuniform_t;
@@ -27,14 +27,23 @@ typedef struct {
   shaderuniform_t shaderVertex;
 
   /** Pointer to an uploaded fragment shader program */
-  shaderuniform_t shaderFrag;
+  GLuint shaderFrag;
 
   /** Pointer to an uploaded shader program linked */
-  shaderuniform_t shaderProgram;
+  GLuint shaderProgram;
 
+  /** Buffer of chars where we store the uniform names */
   char uniformBuffer[SHADER_UNIFORM_NAME_MAX * SHADER_UNIFORM_COUNT];
-  char *uniforms[SHADER_UNIFORM_COUNT];
+
+  /** Array of strings (pointers to the above buffer) of the uniform names */
+  char *uniformNames[SHADER_UNIFORM_COUNT];
   int32_t uniformCount;
+
+  /** Type of each uniform */
+  GLenum types[SHADER_UNIFORM_COUNT];
+
+  /** Texture Slots (which texture slot for GL to use for each uniform) */
+  uint8_t textureSlots[SHADER_UNIFORM_COUNT];
 } shader_t;
 
 /**

src/game/sandbox/game.c

@@ -17,6 +17,9 @@ bool sandboxGameInit(sandboxgame_t *game) {
   assetManagerLoadShader(&game->engine.assetManager, game->scene.assetOwner,
     &game->shader, "shaders/textured.vert", "shaders/textured.frag"
   );
+  assetManagerLoadShader(&game->engine.assetManager, game->scene.assetOwner,
+    &game->shader2, "shaders/test.vert", "shaders/test.frag"
+  );
 
   // Load the texture
   assetManagerLoadScaledTexture(
@@ -28,8 +31,16 @@ bool sandboxGameInit(sandboxgame_t *game) {
     &game->st, &game->texture, 0
   );
 
-  quadInit(&game->quad, 0, 0,0,0,0, 500,500,1,1);
+  assetManagerLoadTexture(
+    &game->engine.assetManager, game->scene.assetOwner,
+    &game->texture, "textures/test_texture.png"
+  );
+
+  cubeInit(&game->quad, 1, 1, 1);
+
   i = renderPassAdd(&game->scene.renderList, &game->shader);
+  i = renderPassAdd(&game->scene.renderList, &game->shader);
+
   return true;
 }
 
@@ -40,34 +51,48 @@ void sandboxGameUpdate(sandboxgame_t *game) {
   n = assetManagerProgressGet(&game->engine.assetManager);
   if(n < 1.0f) return;
 
-  // First pass
   sceneRenderStart(&game->scene);
-  renderListRenderPass(&game->scene.renderList, &game->engine, 0);
-
-  cameraOrtho(&camera,
-    0, game->engine.render.width,
-    game->engine.render.height, 0,
-    0.01f, 1000.0f
-  );
-  cameraLookAt(&camera, 0,0,10, 0,0,0);
 
+  // First pass
   shaderuniform_t uniView = shaderGetUniform(&game->shader, "u_View");
   shaderuniform_t uniProj = shaderGetUniform(&game->shader, "u_Proj");
   shaderuniform_t uniModel = shaderGetUniform(&game->shader, "u_Modl");
   shaderuniform_t uniColor = shaderGetUniform(&game->shader, "u_Colr");
   shaderuniform_t uniTexture = shaderGetUniform(&game->shader, "u_Text");
+
+  renderpass_t *pass =renderListRenderPass(
+    &game->scene.renderList, &game->engine, 0
+  );
+  cameraPerspective(&camera, 45.0f,
+    game->engine.render.width/game->engine.render.height, 0.001f, 1000.0f
+  );
+  cameraLookAt(&camera, 3,3,3, 0,0,0);
   
-  shaderUse(&game->shader);
+  shaderUseCamera(pass->shader, uniView, uniProj, &camera);
-  shaderUseCamera(&game->shader, uniView, uniProj, &camera);
+  shaderUseColor(pass->shader, uniColor, PIXEL_COLOR_WHITE);
-  shaderUseColor(&game->shader, uniColor, PIXEL_COLOR_WHITE);
+  shaderUseTexture(pass->shader, uniTexture, &game->texture);
-  shaderUseTexture(&game->shader, uniTexture, &game->texture);
+  shaderUsePosition(pass->shader, uniModel, 0,0,0,
-  shaderUsePosition(&game->shader, uniModel, 0,0,0, 0,0,0);
+    game->engine.time.current/2.0f, game->engine.time.current, 0
+  );
   primitiveDraw(&game->quad, 0, -1);
 
-  sceneRenderEnd(&game->scene, &game->shader,
+
-    uniView, uniProj, uniModel, &uniTexture,
+  pass = renderListRenderPass(&game->scene.renderList, &game->engine, 1);
-    &game->shader,
+  shaderUsePosition(pass->shader, uniModel, 0,0,0,
-    uniView, uniProj, uniModel, uniTexture
+    -game->engine.time.current/2.0f, -game->engine.time.current, 0
+  );
+  primitiveDraw(&game->quad, 0, -1);
+
+  shaderuniform_t uniTextureSet[2];
+  uniTextureSet[0] = shaderGetUniform(&game->shader2, "u_Text0");
+  uniTextureSet[1] = shaderGetUniform(&game->shader2, "u_Text1");
+
+  sceneRenderEnd(&game->scene, &game->shader2,
+    shaderGetUniform(&game->shader2, "u_View"),
+    shaderGetUniform(&game->shader2, "u_Proj"),
+    shaderGetUniform(&game->shader2, "u_Modl"),
+    uniTextureSet,
+    &game->shader, uniView, uniProj, uniModel, uniTexture
   );
 }
 

src/game/sandbox/game.h

@@ -12,6 +12,7 @@
 #include "../../display/shader/shader.h"
 #include "../../display/primitive/primitive.h"
 #include "../../display/primitive/quad.h"
+#include "../../display/primitive/cube.h"
 #include "../../display/scaledtexture.h"
 #include "../../file/asset.h"
 #include "../../ui/label.h"
@@ -20,13 +21,13 @@
 #include "../../file/xml.h"
 #include "../../engine/engine.h"
 #include "../../display/renderlist.h"
-
 #include "../scene/scene.h"
 
 typedef struct {
   engine_t engine; 
   scene_t scene;
   shader_t shader;
+  shader_t shader2;
   texture_t texture;
   primitive_t quad;
   scaledtexture_t st;