PyGPU: GPUShader: implementation of 'attrs_info_get' method

With the new `attrs_info_get` method, we can get information about
the attributes used in a `GPUShader` and thus have more freedom in the
automatic creation of `GPUVertFormat`s

Reviewed By: fclem, campbellbarton

Differential Revision: https://developer.blender.org/D15764

3 files changed, 54 insertions, 104 deletions

diff --git a/source/blender/gpu/opengl/gl_shader.cc b/source/blender/gpu/opengl/gl_shader.cc
index a08019cc707..1f2ef36716e 100644
--- a/source/blender/gpu/opengl/gl_shader.cc
+++ b/source/blender/gpu/opengl/gl_shader.cc
@@ -1136,108 +1136,6 @@ void GLShader::uniform_int(int location, int comp_len, int array_size, const int
 /** \name GPUVertFormat from Shader
  * \{ */
 
-static uint calc_component_size(const GLenum gl_type)
-{
-  switch (gl_type) {
-    case GL_FLOAT_VEC2:
-    case GL_INT_VEC2:
-    case GL_UNSIGNED_INT_VEC2:
-      return 2;
-    case GL_FLOAT_VEC3:
-    case GL_INT_VEC3:
-    case GL_UNSIGNED_INT_VEC3:
-      return 3;
-    case GL_FLOAT_VEC4:
-    case GL_FLOAT_MAT2:
-    case GL_INT_VEC4:
-    case GL_UNSIGNED_INT_VEC4:
-      return 4;
-    case GL_FLOAT_MAT3:
-      return 9;
-    case GL_FLOAT_MAT4:
-      return 16;
-    case GL_FLOAT_MAT2x3:
-    case GL_FLOAT_MAT3x2:
-      return 6;
-    case GL_FLOAT_MAT2x4:
-    case GL_FLOAT_MAT4x2:
-      return 8;
-    case GL_FLOAT_MAT3x4:
-    case GL_FLOAT_MAT4x3:
-      return 12;
-    default:
-      return 1;
-  }
-}
-
-static void get_fetch_mode_and_comp_type(int gl_type,
-                                         GPUVertCompType *r_comp_type,
-                                         GPUVertFetchMode *r_fetch_mode)
-{
-  switch (gl_type) {
-    case GL_FLOAT:
-    case GL_FLOAT_VEC2:
-    case GL_FLOAT_VEC3:
-    case GL_FLOAT_VEC4:
-    case GL_FLOAT_MAT2:
-    case GL_FLOAT_MAT3:
-    case GL_FLOAT_MAT4:
-    case GL_FLOAT_MAT2x3:
-    case GL_FLOAT_MAT2x4:
-    case GL_FLOAT_MAT3x2:
-    case GL_FLOAT_MAT3x4:
-    case GL_FLOAT_MAT4x2:
-    case GL_FLOAT_MAT4x3:
-      *r_comp_type = GPU_COMP_F32;
-      *r_fetch_mode = GPU_FETCH_FLOAT;
-      break;
-    case GL_INT:
-    case GL_INT_VEC2:
-    case GL_INT_VEC3:
-    case GL_INT_VEC4:
-      *r_comp_type = GPU_COMP_I32;
-      *r_fetch_mode = GPU_FETCH_INT;
-      break;
-    case GL_UNSIGNED_INT:
-    case GL_UNSIGNED_INT_VEC2:
-    case GL_UNSIGNED_INT_VEC3:
-    case GL_UNSIGNED_INT_VEC4:
-      *r_comp_type = GPU_COMP_U32;
-      *r_fetch_mode = GPU_FETCH_INT;
-      break;
-    default:
-      BLI_assert(0);
-  }
-}
-
-void GLShader::vertformat_from_shader(GPUVertFormat *format) const
-{
-  GPU_vertformat_clear(format);
-
-  GLint attr_len;
-  glGetProgramiv(shader_program_, GL_ACTIVE_ATTRIBUTES, &attr_len);
-
-  for (int i = 0; i < attr_len; i++) {
-    char name[256];
-    GLenum gl_type;
-    GLint size;
-    glGetActiveAttrib(shader_program_, i, sizeof(name), nullptr, &size, &gl_type, name);
-
-    /* Ignore OpenGL names like `gl_BaseInstanceARB`, `gl_InstanceID` and `gl_VertexID`. */
-    if (glGetAttribLocation(shader_program_, name) == -1) {
-      continue;
-    }
-
-    GPUVertCompType comp_type;
-    GPUVertFetchMode fetch_mode;
-    get_fetch_mode_and_comp_type(gl_type, &comp_type, &fetch_mode);
-
-    int comp_len = calc_component_size(gl_type) * size;
-
-    GPU_vertformat_attr_add(format, name, comp_type, comp_len, fetch_mode);
-  }
-}
-
 int GLShader::program_handle_get() const
 {
   return (int)this->shader_program_;
diff --git a/source/blender/gpu/opengl/gl_shader.hh b/source/blender/gpu/opengl/gl_shader.hh
index 2774b24cdbe..bebbb2fa82e 100644
--- a/source/blender/gpu/opengl/gl_shader.hh
+++ b/source/blender/gpu/opengl/gl_shader.hh
@@ -67,8 +67,6 @@ class GLShader : public Shader {
   void uniform_float(int location, int comp_len, int array_size, const float *data) override;
   void uniform_int(int location, int comp_len, int array_size, const int *data) override;
 
-  void vertformat_from_shader(GPUVertFormat *format) const override;
-
   /** DEPRECATED: Kept only because of BGL API. */
   int program_handle_get() const override;
 
diff --git a/source/blender/gpu/opengl/gl_shader_interface.cc b/source/blender/gpu/opengl/gl_shader_interface.cc
index 4623a14dab3..b230706b020 100644
--- a/source/blender/gpu/opengl/gl_shader_interface.cc
+++ b/source/blender/gpu/opengl/gl_shader_interface.cc
@@ -16,6 +16,7 @@
 
 #include "GPU_capabilities.h"
 
+using namespace blender::gpu::shader;
 namespace blender::gpu {
 
 /* -------------------------------------------------------------------- */
@@ -151,6 +152,52 @@ static inline int ssbo_binding(int32_t program, uint32_t ssbo_index)
 /** \name Creation / Destruction
  * \{ */
 
+static Type gpu_type_from_gl_type(int gl_type)
+{
+  switch (gl_type) {
+    case GL_FLOAT:
+      return Type::FLOAT;
+    case GL_FLOAT_VEC2:
+      return Type::VEC2;
+    case GL_FLOAT_VEC3:
+      return Type::VEC3;
+    case GL_FLOAT_VEC4:
+      return Type::VEC4;
+    case GL_FLOAT_MAT3:
+      return Type::MAT3;
+    case GL_FLOAT_MAT4:
+      return Type::MAT4;
+    case GL_UNSIGNED_INT:
+      return Type::UINT;
+    case GL_UNSIGNED_INT_VEC2:
+      return Type::UVEC2;
+    case GL_UNSIGNED_INT_VEC3:
+      return Type::UVEC3;
+    case GL_UNSIGNED_INT_VEC4:
+      return Type::UVEC4;
+    case GL_INT:
+      return Type::INT;
+    case GL_INT_VEC2:
+      return Type::IVEC2;
+    case GL_INT_VEC3:
+      return Type::IVEC3;
+    case GL_INT_VEC4:
+      return Type::IVEC4;
+    case GL_BOOL:
+      return Type::BOOL;
+    case GL_FLOAT_MAT2:
+    case GL_FLOAT_MAT2x3:
+    case GL_FLOAT_MAT2x4:
+    case GL_FLOAT_MAT3x2:
+    case GL_FLOAT_MAT3x4:
+    case GL_FLOAT_MAT4x2:
+    case GL_FLOAT_MAT4x3:
+    default:
+      BLI_assert(0);
+  }
+  return Type::FLOAT;
+}
+
 GLShaderInterface::GLShaderInterface(GLuint program)
 {
   /* Necessary to make #glUniform works. */
@@ -246,6 +293,9 @@ GLShaderInterface::GLShaderInterface(GLuint program)
 
     name_buffer_offset += set_input_name(input, name, name_len);
     enabled_attr_mask_ |= (1 << input->location);
+
+    /* Used in `GPU_shader_get_attribute_info`. */
+    attr_types_[input->location] = (uint8_t)gpu_type_from_gl_type(type);
   }
 
   /* Uniform Blocks */
@@ -405,7 +455,11 @@ GLShaderInterface::GLShaderInterface(GLuint program, const shader::ShaderCreateI
     }
     if (input->location != -1) {
       enabled_attr_mask_ |= (1 << input->location);
+
+      /* Used in `GPU_shader_get_attribute_info`. */
+      attr_types_[input->location] = (uint8_t)attr.type;
     }
+
     input++;
   }