Add support for 2x2 matrices

src/gpu/vk/GrVkUniformHandler.cpp

 /*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
 
 #include "GrVkUniformHandler.h"
 #include "glsl/GrGLSLProgramBuilder.h"
 
 // To determine whether a current offset is aligned, we can just 'and' the lowest bits with the
 // alignment mask. A value of 0 means aligned, any other value is how many bytes past alignment we
 // are. This works since all alignments are powers of 2. The mask is always (alignment - 1).
 // This alignment mask will give correct alignments for using the std430 block layout. If you want
 // the std140 alignment, you can use this, but then make sure if you have an array type it is
 // aligned to 16 bytes (i.e. has mask of 0xF).
 uint32_t grsltype_to_alignment_mask(GrSLType type) {
     SkASSERT(GrSLTypeIsFloatType(type));
     static const uint32_t kAlignments[kGrSLTypeCount] = {
         0x0, // kVoid_GrSLType, should never return this
         0x3, // kFloat_GrSLType
         0x7, // kVec2f_GrSLType
         0xF, // kVec3f_GrSLType
         0xF, // kVec4f_GrSLType
+        0xF, // kMat22f_GrSLType

[egdaniel, 2016/03/07 18:51:26]

so this function technically returns things in std430 layout. Which means for
arrays (which a matrix is) it is the alignment of the column vecs, so the
alignment of a vec2. Thus the alignment for a mat22f would be 8 bytes and thus a
mask of 0x7.

[egdaniel, 2016/03/07 21:20:03]

Can you just make this change 0x7

[Chris Dalton, 2016/03/07 22:17:12]

Done.

         0xF, // kMat33f_GrSLType
         0xF, // kMat44f_GrSLType
         0x0, // Sampler2D_GrSLType, should never return this
         0x0, // SamplerExternal_GrSLType, should never return this
     };
     GR_STATIC_ASSERT(0 == kVoid_GrSLType);
     GR_STATIC_ASSERT(1 == kFloat_GrSLType);
     GR_STATIC_ASSERT(2 == kVec2f_GrSLType);
     GR_STATIC_ASSERT(3 == kVec3f_GrSLType);
     GR_STATIC_ASSERT(4 == kVec4f_GrSLType);
-    GR_STATIC_ASSERT(5 == kMat33f_GrSLType);
-    GR_STATIC_ASSERT(6 == kMat44f_GrSLType);
-    GR_STATIC_ASSERT(7 == kSampler2D_GrSLType);
-    GR_STATIC_ASSERT(8 == kSamplerExternal_GrSLType);
+    GR_STATIC_ASSERT(5 == kMat22f_GrSLType);
+    GR_STATIC_ASSERT(6 == kMat33f_GrSLType);
+    GR_STATIC_ASSERT(7 == kMat44f_GrSLType);
+    GR_STATIC_ASSERT(8 == kSampler2D_GrSLType);
+    GR_STATIC_ASSERT(9 == kSamplerExternal_GrSLType);
     GR_STATIC_ASSERT(SK_ARRAY_COUNT(kAlignments) == kGrSLTypeCount);
     return kAlignments[type];
 }
 
 /** Returns the size in bytes taken up in vulkanbuffers for floating point GrSLTypes.
     For non floating point type returns 0 */
 static inline uint32_t grsltype_to_vk_size(GrSLType type) {
     SkASSERT(GrSLTypeIsFloatType(type));
     static const uint32_t kSizes[] = {
         0,                        // kVoid_GrSLType
         sizeof(float),            // kFloat_GrSLType
         2 * sizeof(float),        // kVec2f_GrSLType
         3 * sizeof(float),        // kVec3f_GrSLType
         4 * sizeof(float),        // kVec4f_GrSLType
+        8 * sizeof(float),        // kMat22f_GrSLType

[egdaniel, 2016/03/07 18:51:26]

This function may need some reworking since we have decide what we mean by size.
The size of a mat2x2 in a uniform buffer, std140 layout, will be 2*
sizeof(vec4). In a push constant buffer, std430 layout, it will be 2 *
sizeof(vec2). This is one of the reasons I was saying adding a 2x2 matrix makes
things more complicated here. For a Mat3x3 (and thus a column of vec3), always
acts like a vec4.

So either we need to make 2 different size helper functions, or we need a way to
pass in some variable to this function so it knows what the size of a matrix
column should be.

[egdaniel, 2016/03/07 21:20:03]

Just add a comment after Mat22f_GrSLType saying something along the lines that
this needs to be fixed

[Chris Dalton, 2016/03/07 22:17:12]

Done.

         12 * sizeof(float),       // kMat33f_GrSLType
         16 * sizeof(float),       // kMat44f_GrSLType
         0,                        // kSampler2D_GrSLType
         0,                        // kSamplerExternal_GrSLType
         0,                        // kSampler2DRect_GrSLType
         0,                        // kBool_GrSLType
         0,                        // kInt_GrSLType
         0,                        // kUint_GrSLType
     };
     return kSizes[type];
 
     GR_STATIC_ASSERT(0 == kVoid_GrSLType);
     GR_STATIC_ASSERT(1 == kFloat_GrSLType);
     GR_STATIC_ASSERT(2 == kVec2f_GrSLType);
     GR_STATIC_ASSERT(3 == kVec3f_GrSLType);
     GR_STATIC_ASSERT(4 == kVec4f_GrSLType);
-    GR_STATIC_ASSERT(5 == kMat33f_GrSLType);
-    GR_STATIC_ASSERT(6 == kMat44f_GrSLType);
-    GR_STATIC_ASSERT(7 == kSampler2D_GrSLType);
-    GR_STATIC_ASSERT(8 == kSamplerExternal_GrSLType);
-    GR_STATIC_ASSERT(9 == kSampler2DRect_GrSLType);
-    GR_STATIC_ASSERT(10 == kBool_GrSLType);
-    GR_STATIC_ASSERT(11 == kInt_GrSLType);
-    GR_STATIC_ASSERT(12 == kUint_GrSLType);
-    GR_STATIC_ASSERT(13 == kGrSLTypeCount);
+    GR_STATIC_ASSERT(5 == kMat22f_GrSLType);
+    GR_STATIC_ASSERT(6 == kMat33f_GrSLType);
+    GR_STATIC_ASSERT(7 == kMat44f_GrSLType);
+    GR_STATIC_ASSERT(8 == kSampler2D_GrSLType);
+    GR_STATIC_ASSERT(9 == kSamplerExternal_GrSLType);
+    GR_STATIC_ASSERT(10 == kSampler2DRect_GrSLType);
+    GR_STATIC_ASSERT(11 == kBool_GrSLType);
+    GR_STATIC_ASSERT(12 == kInt_GrSLType);
+    GR_STATIC_ASSERT(13 == kUint_GrSLType);
+    GR_STATIC_ASSERT(SK_ARRAY_COUNT(kSizes) == kGrSLTypeCount);
 }
 
 
 // Given the current offset into the ubo, calculate the offset for the uniform we're trying to add
 // taking into consideration all alignment requirements. The uniformOffset is set to the offset for
 // the new uniform, and currentOffset is updated to be the offset to the end of the new uniform.
 void get_ubo_aligned_offset(uint32_t* uniformOffset,
                             uint32_t* currentOffset,
                             GrSLType type,
                             int arrayCount) {
     uint32_t alignmentMask = grsltype_to_alignment_mask(type);
     // We want to use the std140 layout here, so we must make arrays align to 16 bytes.
     if (arrayCount) {

[egdaniel, 2016/03/07 18:51:26]

we could make this if (arrayCount || Mat22 == type). Not the cleanest but would
give use the correct alignments.

[egdaniel, 2016/03/07 21:20:03]

Add assert in this function the type != Mat22

[Chris Dalton, 2016/03/07 22:17:12]

Done.

         alignmentMask = 0xF;
     }
     uint32_t offsetDiff = *currentOffset & alignmentMask;
     if (offsetDiff != 0) {
         offsetDiff = alignmentMask - offsetDiff + 1;
     }
     *uniformOffset = *currentOffset + offsetDiff;
     SkASSERT(sizeof(float) == 4);
     if (arrayCount) {
         uint32_t elementSize = SkTMax<uint32_t>(16, grsltype_to_vk_size(type));
@@ skipping 88 matching lines @@
         }
     }
     if (!uniformsString.isEmpty()) {
         const char* stage = (visibility == kVertex_GrShaderFlag) ? "vertex" : "fragment";
         out->appendf("layout (set=%d, binding=%d) uniform %sUniformBuffer\n{\n",
                      kUniformBufferDescSet, uniformBinding, stage);
         out->appendf("%s\n};\n", uniformsString.c_str());
     }
 }