From d443f0a92183c94eaa0c33dddbb450eb8fe2fd07 Mon Sep 17 00:00:00 2001
From: Tony Wasserka <NeoBrainX@gmail.com>
Date: Sat, 26 Jul 2014 16:19:11 +0200
Subject: Pica: Implement vertex loading.

---
 src/video_core/command_processor.cpp | 81 +++++++++++++++++++++++++++++++++++-
 1 file changed, 80 insertions(+), 1 deletion(-)

(limited to 'src/video_core/command_processor.cpp')

diff --git a/src/video_core/command_processor.cpp b/src/video_core/command_processor.cpp
index 515c407e..e909c8c3 100644
--- a/src/video_core/command_processor.cpp
+++ b/src/video_core/command_processor.cpp
@@ -4,6 +4,7 @@
 
 #include "pica.h"
 #include "command_processor.h"
+#include "math.h"
 
 
 namespace Pica {
@@ -17,7 +18,85 @@ static inline void WritePicaReg(u32 id, u32 value) {
     registers[id] = value;
 
     switch(id) {
-        // TODO: Perform actions for anything which requires special treatment here...
+        // It seems like these trigger vertex rendering
+        case PICA_REG_INDEX(trigger_draw):
+        case PICA_REG_INDEX(trigger_draw_indexed):
+        {
+            const auto& attribute_config = registers.vertex_attributes;
+            const u8* const base_address = Memory::GetPointer(attribute_config.GetBaseAddress());
+
+            // Information about internal vertex attributes
+            const u8* vertex_attribute_sources[16];
+            u32 vertex_attribute_strides[16];
+            u32 vertex_attribute_formats[16];
+            u32 vertex_attribute_elements[16];
+            u32 vertex_attribute_element_size[16];
+
+            // Setup attribute data from loaders
+            for (int loader = 0; loader < 12; ++loader) {
+                const auto& loader_config = attribute_config.attribute_loaders[loader];
+
+                const u8* load_address = base_address + loader_config.data_offset;
+
+                // TODO: What happens if a loader overwrites a previous one's data?
+                for (int component = 0; component < loader_config.component_count; ++component) {
+                    u32 attribute_index = loader_config.GetComponent(component);
+                    vertex_attribute_sources[attribute_index] = load_address;
+                    vertex_attribute_strides[attribute_index] = loader_config.byte_count;
+                    vertex_attribute_formats[attribute_index] = (u32)attribute_config.GetFormat(attribute_index);
+                    vertex_attribute_elements[attribute_index] = attribute_config.GetNumElements(attribute_index);
+                    vertex_attribute_element_size[attribute_index] = attribute_config.GetElementSizeInBytes(attribute_index);
+                    load_address += attribute_config.GetStride(attribute_index);
+                }
+            }
+
+            // Load vertices
+            bool is_indexed = (id == PICA_REG_INDEX(trigger_draw_indexed));
+
+            const auto& index_info = registers.index_array;
+            const u8* index_address_8 = (u8*)base_address + index_info.offset;
+            const u16* index_address_16 = (u16*)index_address_8;
+            bool index_u16 = (bool)index_info.format;
+
+            for (int index = 0; index < registers.num_vertices; ++index)
+            {
+                int vertex = is_indexed ? (index_u16 ? index_address_16[index] : index_address_8[index]) : index;
+
+                if (is_indexed) {
+                    // TODO: Implement some sort of vertex cache!
+                }
+
+                // Initialize data for the current vertex
+                struct {
+                    Math::Vec4<float24> attr[16];
+                } input;
+
+                for (int i = 0; i < attribute_config.GetNumTotalAttributes(); ++i) {
+                    for (int comp = 0; comp < vertex_attribute_elements[i]; ++comp) {
+                        const u8* srcdata = vertex_attribute_sources[i] + vertex_attribute_strides[i] * vertex + comp * vertex_attribute_element_size[i];
+                        const float srcval = (vertex_attribute_formats[i] == 0) ? *(s8*)srcdata :
+                                             (vertex_attribute_formats[i] == 1) ? *(u8*)srcdata :
+                                             (vertex_attribute_formats[i] == 2) ? *(s16*)srcdata :
+                                                                                  *(float*)srcdata;
+                        input.attr[i][comp] = float24::FromFloat32(srcval);
+                        DEBUG_LOG(GPU, "Loaded component %x of attribute %x for vertex %x (index %x) from 0x%08x + 0x%08x + 0x%04x: %f",
+                                  comp, i, vertex, index,
+                                  attribute_config.GetBaseAddress(),
+                                  vertex_attribute_sources[i] - base_address,
+                                  srcdata - vertex_attribute_sources[i],
+                                  input.attr[i][comp].ToFloat32());
+                    }
+                }
+                // TODO: Run vertex data through vertex shader
+
+                if (is_indexed) {
+                    // TODO: Add processed vertex to vertex cache!
+                }
+
+                // TODO: Submit vertex to primitive assembly
+            }
+            break;
+        }
 
         default:
             break;
-- 
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