From 4646ba9c482d1f914a4fcdd29eeb8cdb4848acc3 Mon Sep 17 00:00:00 2001
From: Jannik Vogel <email@jannikvogel.de>
Date: Tue, 25 Aug 2015 06:44:06 +0200
Subject: [PATCH] Use uniform buffer objects

---
 hw/xbox/nv2a.c         | 45 +++++++++++++++++++++++++++++++-----------
 hw/xbox/nv2a_shaders.c | 10 ++--------
 hw/xbox/nv2a_shaders.h |  2 +-
 hw/xbox/nv2a_vsh.c     |  4 +++-
 4 files changed, 39 insertions(+), 22 deletions(-)

diff --git a/hw/xbox/nv2a.c b/hw/xbox/nv2a.c
index c277c4d926..5cc6a23911 100644
--- a/hw/xbox/nv2a.c
+++ b/hw/xbox/nv2a.c
@@ -1553,6 +1553,8 @@ typedef struct PGRAPHState {
     GLuint gl_element_buffer;
     GLuint gl_memory_buffer;
 
+    GLuint gl_vertex_constants_buffer;
+
     GLuint gl_vertex_array;
 
     uint32_t regs[0x2000];
@@ -2902,6 +2904,13 @@ static void pgraph_bind_shaders(PGRAPHState *pg)
     } else {
         pg->shader_binding = generate_shaders(state);
 
+        /* Bind uniform blocks */
+        if (pg->shader_binding->gl_constants_loc != GL_INVALID_INDEX) {
+            glUniformBlockBinding(pg->shader_binding->gl_program,
+                                  pg->shader_binding->gl_constants_loc,
+                                  0 /* FIXME: Use #define */);
+        }
+
         /* cache it */
         ShaderState *cache_state = g_malloc(sizeof(*cache_state));
         memcpy(cache_state, &state, sizeof(*cache_state));
@@ -3097,18 +3106,6 @@ static void pgraph_bind_shaders(PGRAPHState *pg)
     } else if (vertex_program) {
         /* update vertex program constants */
 
-        for (i=0; i<NV2A_VERTEXSHADER_CONSTANTS; i++) {
-            VertexShaderConstant *constant = &pg->constants[i];
-            if (!constant->dirty && !binding_changed) continue;
-
-            GLint loc = pg->shader_binding->vsh_constant_loc[i];
-            //assert(loc != -1);
-            if (loc != -1) {
-                glUniform4fv(loc, 1, (const GLfloat*)constant->data);
-            }
-            constant->dirty = false;
-        }
-
         GLint loc = glGetUniformLocation(pg->shader_binding->gl_program,
                                           "surfaceSize");
         if (loc != -1) {
@@ -3123,6 +3120,23 @@ static void pgraph_bind_shaders(PGRAPHState *pg)
         }
 
     }
+
+    /* Update constants */
+    if (pg->shader_binding->gl_constants_loc != GL_INVALID_INDEX) {
+        /* FIXME: Can be done on buffer creation? */
+        glBindBufferBase(GL_UNIFORM_BUFFER, 0 /* FIXME: Use def */,
+                         pg->gl_vertex_constants_buffer);
+        for (i=0; i<NV2A_VERTEXSHADER_CONSTANTS; i++) {
+            VertexShaderConstant *constant = &pg->constants[i];
+            if (!constant->dirty) continue;
+
+            /* FIXME: Query GL_UNIFORM_ARRAY_STRIDE instead of assuming 16 */
+
+            glBufferSubData(GL_UNIFORM_BUFFER, i * 16, 16, constant->data);
+            constant->dirty = false;
+        }
+    }
+
     NV2A_GL_DGROUP_END();
 }
 
@@ -3532,6 +3546,13 @@ static void pgraph_init(NV2AState *d)
     glGenBuffers(1, &pg->gl_inline_array_buffer);
     glGenBuffers(1, &pg->gl_element_buffer);
 
+    glGenBuffers(1, &pg->gl_vertex_constants_buffer);
+    glBindBuffer(GL_UNIFORM_BUFFER, pg->gl_vertex_constants_buffer);
+    glBufferData(GL_UNIFORM_BUFFER,
+                 16 * NV2A_VERTEXSHADER_CONSTANTS,
+                 NULL,
+                 GL_DYNAMIC_DRAW);
+
     glGenBuffers(1, &pg->gl_memory_buffer);
     glBindBuffer(GL_ARRAY_BUFFER, pg->gl_memory_buffer);
     glBufferData(GL_ARRAY_BUFFER,
diff --git a/hw/xbox/nv2a_shaders.c b/hw/xbox/nv2a_shaders.c
index e6cdc02321..3ee35610db 100644
--- a/hw/xbox/nv2a_shaders.c
+++ b/hw/xbox/nv2a_shaders.c
@@ -593,14 +593,8 @@ ShaderBinding* generate_shaders(const ShaderState state)
             ret->psh_constant_loc[i][j] = glGetUniformLocation(program, tmp);
         }
     }
-    if (state.vertex_program) {
-        /* lookup vertex shader bindings */
-        for(i = 0; i < NV2A_VERTEXSHADER_CONSTANTS; i++) {
-            char tmp[8];
-            snprintf(tmp, sizeof(tmp), "c[%d]", i);
-            ret->vsh_constant_loc[i] = glGetUniformLocation(program, tmp);
-        }
-    }
+
+    ret->gl_constants_loc = glGetUniformBlockIndex(program, "VertexConstants");
 
     return ret;
 }
diff --git a/hw/xbox/nv2a_shaders.h b/hw/xbox/nv2a_shaders.h
index 3271cb5415..c26c85d9b4 100644
--- a/hw/xbox/nv2a_shaders.h
+++ b/hw/xbox/nv2a_shaders.h
@@ -87,7 +87,7 @@ typedef struct ShaderState {
 typedef struct ShaderBinding {
     GLuint gl_program;
     GLint psh_constant_loc[9][2];
-    GLint vsh_constant_loc[NV2A_VERTEXSHADER_CONSTANTS];
+    GLint gl_constants_loc;
 } ShaderBinding;
 
 ShaderBinding* generate_shaders(const ShaderState state);
diff --git a/hw/xbox/nv2a_vsh.c b/hw/xbox/nv2a_vsh.c
index 3e43a284cc..90316817cd 100644
--- a/hw/xbox/nv2a_vsh.c
+++ b/hw/xbox/nv2a_vsh.c
@@ -567,7 +567,9 @@ static const char* vsh_header =
 
 
     /* All constants in 1 array declaration */
-   "uniform vec4 c[192];\n"
+   "layout(shared) uniform VertexConstants {\n"
+   "  uniform vec4 c[192];\n"
+   "};"
    "\n"
    "uniform vec2 clipRange;\n"
    "uniform vec2 surfaceSize;\n"