GPU: ShaderInterface: Refactor to setup all uniform at creation time

This remove the complexity of queriying the locations at runtime and
allows for more performance and upfront binding specifications.

The benefit of doing everything at creation time is that we can assign binding
points in a predictable order which is going to be somewhat the same for
every similar shader.

This also rewrite GPU_vertformat_from_shader to not use shaderface.

This is to keep the shaderface simple. If it becomes necessary to not query
the shader after creation (i.e: vulkan?) we could just create the vert
format in advance at compilation for PyGPU shaders.

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D7879

1 files changed, 18 insertions, 17 deletions

diff --git a/source/blender/gpu/GPU_shader_interface.h b/source/blender/gpu/GPU_shader_interface.h
index 3e7bad409a3..91064719995 100644
--- a/source/blender/gpu/GPU_shader_interface.h
+++ b/source/blender/gpu/GPU_shader_interface.h
@@ -64,33 +64,34 @@ typedef enum {
 } GPUUniformBuiltin;
 
 typedef struct GPUShaderInput {
-  struct GPUShaderInput *next;
   uint32_t name_offset;
-  uint name_hash;
-  /** Only for uniform inputs. */
-  GPUUniformBuiltin builtin_type;
-  /** Only for attribute inputs. */
-  uint32_t gl_type;
-  /** Only for attribute inputs. */
-  int32_t size;
+  uint32_t name_hash;
   int32_t location;
+  /** Defined at interface creation or in shader. Only for Samplers, UBOs and Vertex Attribs. */
+  int32_t binding;
 } GPUShaderInput;
 
-#define GPU_NUM_SHADERINTERFACE_BUCKETS 257
 #define GPU_SHADERINTERFACE_REF_ALLOC_COUNT 16
 
 typedef struct GPUShaderInterface {
-  int32_t program;
-  uint32_t name_buffer_offset;
-  GPUShaderInput *attr_buckets[GPU_NUM_SHADERINTERFACE_BUCKETS];
-  GPUShaderInput *uniform_buckets[GPU_NUM_SHADERINTERFACE_BUCKETS];
-  GPUShaderInput *ubo_buckets[GPU_NUM_SHADERINTERFACE_BUCKETS];
-  GPUShaderInput *builtin_uniforms[GPU_NUM_UNIFORMS];
+  /** Buffer containing all inputs names separated by '\0'. */
   char *name_buffer;
-  struct GPUBatch **batches; /* references to batches using this interface */
+  /** Reference to GPUBatches using this interface */
+  struct GPUBatch **batches;
   uint batches_len;
-  /** All enabled attributes in this shader. Used to set default values for unbound attributes. */
+  /** Input counts. */
+  uint attribute_len;
+  uint ubo_len;
+  uint uniform_len;
+  /** Enabled bindpoints that needs to be fed with data. */
   uint16_t enabled_attr_mask;
+  uint16_t enabled_ubo_mask;
+  uint64_t enabled_tex_mask;
+  /** Opengl Location of builtin uniforms. Fast access, no lookup needed. */
+  /* TODO replace by location only array. */
+  GPUShaderInput builtins[GPU_NUM_UNIFORMS];
+  /** Flat array. In this order: Attributes, Ubos, Uniforms. */
+  GPUShaderInput inputs[0];
 } GPUShaderInterface;
 
 GPUShaderInterface *GPU_shaderinterface_create(int32_t program_id);