Add render pipeline customization

2 files changed, 118 insertions, 9 deletions

diff --git a/src/include/daw/rendering.h b/src/include/daw/rendering.h
index 9c4b647..17d3728 100644
--- a/src/include/daw/rendering.h
+++ b/src/include/daw/rendering.h
@@ -204,15 +204,16 @@ u32 ShaderBuffer_get_gl_accesstype(u64 flags);
 u32 ShaderBuffer_get_gl_datatype(u64 flags);
 
 /* Misc */
-void r_perspective(f32 fov, Camera *c);
-void r_perspective_ortho(f32 sz, Camera *c);
+void r_perspective(Camera *c, f32 fov, ivec2 windowsize);
+void r_perspective_ortho(Camera *c, f32 sz, ivec2 windowsize);
 
 void r_set_camera(Camera* c);
-void r_reset_camera(Camera* c);
+void r_reset_camera(Camera* c, ivec2 windowsize);
 
 //void window_size_callback(GLFWwindow* window, i32 width, i32 height);
 
-void engine_draw_model(RenderObject* o, vec3 pos);
+// 3D positional coordinates and scale in last element of `pos`
+void engine_draw_model(RenderObject* o, vec4 pos);
 
 typedef struct {
   vec3 pos;
@@ -220,7 +221,89 @@ typedef struct {
   RenderObject* model;
 } RenderDrawCall;
 
-// TODO make all the shader buffers a list
+typedef enum {
+  BufferType_frame   = 1,
+  BufferType_texture = 2,
+  BufferType_render  = 3,
+  BufferType_buffer  = 4,
+
+} BufferType;
+
+// Buffer parameter: Frame buffer
+// Buffer parameter: Texture buffer
+#define BUFFERPARAMETER_TEXTURE_1D 1
+#define BUFFERPARAMETER_TEXTURE_2D 2
+#define BUFFERPARAMETER_TEXTURE_3D 3
+#define BUFFERPARAMETER_TEXTURE_4D 4
+
+#define BUFFERPARAMETER_TEXTURE_FMT_RGBA8 (1 << 4)
+#define BUFFERPARAMETER_TEXTURE_FMT_SRGB8 (2 << 4)
+#define BUFFERPARAMETER_TEXTURE_FMT_SRGBA8 (3 << 4)
+
+//TODO: texture formats
+
+// Buffer parameter: Buffer buffer
+#define BUFFERPARAMETER_BUFFER_DEPTH   1
+#define BUFFERPARAMETER_BUFFER_STENCIL 2
+
+// `buffer_definition` has the first 4 bits for the type,
+#define BUFFERPARAMETER_MASK_TYPE      ((1 << 4) - 1)
+// next 16 bits for the type-specific parameters
+#define BUFFERPARAMETER_MASK_PARAMETER (((1 << 16) - 1) << 4)
+
+#define BUFFERPARAMETER_GET_TYPE(bufferparam) \
+  (BufferType)(bufferparam & BUFFERPARAMETER_MASK_TYPE)
+#define BUFFERPARAMETER_GET_PARAMETER(bufferparam) \
+  ((bufferparam & BUFFERPARAMETER_MASK_TYPE) >> 4)
+
+#define BUFFERPARAMETER_SET_TYPE(bufferparam, type) \
+  (BufferType)((bufferparam & ~BUFFERPARAMETER_MASK_TYPE) | type)
+#define BUFFERPARAMETER_SET_PARAMETER(bufferparam, param) \
+  ((bufferparam & ~BUFFERPARAMETER_MASK_PARAMETER) | (param << 4))
+
+typedef struct {
+  i32 num_attached_buffers;
+  ivec4 dimensions; // All objects attached to a framebuffer (in OpenGL) must have same size
+} FramebufferParameters;
+
+// A render target takes a bunch of drawcalls, and renders it to a texture.
+// TODO: user runs "init" for their rendertarget(s) "stack", possibly using some
+// predefined macro "DEFAULT_RENDERTARGETS". Requires user to specify number of lights et. al.
+typedef struct {
+  // glFrameBuffer
+  usize framebuffer_len;
+
+  // glTexture / glRenderBuffer / glBuffer / glWhatever
+  usize buffer_len;
+
+  u32 *framebuffer;
+  u32 *buffer;
+
+  // Number of buffers attached to each of the framebuffers. Used to iteratively
+  // get all buffers by summing the previous sizes to get the first buffer
+  // associated with the current.
+  FramebufferParameters *framebuffer_parameters;
+
+  // Stores per-buffer type, and type-specific parameters.
+  u32 *buffer_parameters;
+
+  // One cam per framebuffer
+  Camera *cam;
+
+  //// Called when window is resized with new width and height. Set to NULL to
+  //// skip changing texture_size. Comparable to glViewport.
+  //// This function can be heavy due to it destroying and re-creating framebuffers.
+  //// Which requires me to store the parameters that they we're created with.
+  //void (**framebuffer_size_callback)(ivec2*,ivec2);
+
+  //// Called when window is resized. Calls the respective texture_size_callback function at
+  //// the same index if not null. The camera resize callback function is then
+  //// called with the new dimensions of the texture.
+  //// Set to NULL to skip changing the camera size/perspective.
+  void (**camera_reset_callback)(Camera*,ivec2);
+} RenderTargets;
+
+void r_camera_reset_default(Camera* c, ivec2 windowsize);
 
 RenderObject RenderObject_new(
     Shader* shader,
@@ -242,6 +325,20 @@ ShaderType guess_shadertype_from_filename(const char *restrict fname);
 
 Texture createTextureFromImageData(unsigned char* image_data, i32 width, i32 height, u8 components);
 
+void r_create_framebuffers(void* restrict ctx, u32* restrict framebuffer_array, usize num_targets);
+void r_destroy_framebuffers(void* restrict ctx, u32* restrict framebuffer_array, usize num_targets);
+void r_create_textures(void *restrict ctx, u32* restrict texture_array, u32* restrict texture_types, ivec4* restrict texture_sizes, usize num_targets);
+void r_destroy_textures(void *restrict ctx, u32* textures, usize num_textures);
+
+void r_init_renderstack(
+    usize num_fbuf, usize num_buf,
+    FramebufferParameters *restrict fb_params,
+    u32 *restrict buffer_params
+    );
+
+//static void r_create_renderbuffers(GladGLContext* restrict ctx, u32* restrict renderbuffer_array, u32* restrict renderbuffer_types, ivec2* restrict renderbuffer_sizes, usize num_targets);
+
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/include/daw/window.h b/src/include/daw/window.h
index f445860..44ea1fa 100644
--- a/src/include/daw/window.h
+++ b/src/include/daw/window.h
@@ -12,6 +12,10 @@ extern "C" {
 
 #include <daw/rendering.h>
 
+#define DAW_WINDOW_VSYNC      (1 << 0)
+#define DAW_WINDOW_FULLSCREEN (1 << 1)
+#define DAW_WINDOW_RESIZEABLE (1 << 2)
+
 typedef enum {
   WINDOW_FRAMEWORK_NONE = 0,
   WINDOW_FRAMEWORK_GLFW,
@@ -39,11 +43,13 @@ typedef struct {
   usize bindings_sz;
   usize bindings_len;
   i_ctx** bindings;
-} Window;
 
-#define DAW_WINDOW_VSYNC      (1 << 0)
-#define DAW_WINDOW_FULLSCREEN (1 << 1)
-#define DAW_WINDOW_RESIZEABLE (1 << 2)
+  /* The first element in the stack is the one presented to the screen. This is
+   * usually used for post-processing effects and can depend on previous
+   * RenderTextures. Use cases vary from shadowmapping, secondary in-game
+   * cameras, and UI. */
+  RenderTargets *render_targets;
+} Window;
 
 // Whether or not it is clever to force API consistency using a struct like this
 // can be debated, at the time of writing it seemed like a smart idea.
@@ -97,6 +103,12 @@ void render_present(Window* w);
 void window_reset_drawing(void);
 void render(Window* w);
 
+void window_init_renderstack(Window *restrict w,
+    usize num_fbuf, usize num_buf,
+    FramebufferParameters *restrict fb_params,
+    u32 *restrict buffer_params
+    );
+
 void get_mousepos(double *x, double *y);
 void window_get_size(ivec2* dst);