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Merge pull request #2884 from wwylele/clip

gl_rasterizer: add clipping plane z<=0 defined in PICA
This commit is contained in:
bunnei 2017-08-21 13:24:12 -04:00 committed by GitHub
commit f84c965dec
6 changed files with 28 additions and 10 deletions

View file

@ -28,6 +28,9 @@ MICROPROFILE_DEFINE(OpenGL_Blits, "OpenGL", "Blits", MP_RGB(100, 100, 255));
MICROPROFILE_DEFINE(OpenGL_CacheManagement, "OpenGL", "Cache Mgmt", MP_RGB(100, 255, 100));
RasterizerOpenGL::RasterizerOpenGL() : shader_dirty(true) {
// Clipping plane 0 is always enabled for PICA fixed clip plane z <= 0
state.clip_distance[0] = true;
// Create sampler objects
for (size_t i = 0; i < texture_samplers.size(); ++i) {
texture_samplers[i].Create();

View file

@ -1112,7 +1112,10 @@ vec4 secondary_fragment_color = vec4(0.0);
"gl_FragCoord.y < scissor_y2)) discard;\n";
}
out += "float z_over_w = 1.0 - gl_FragCoord.z * 2.0;\n";
// After perspective divide, OpenGL transform z_over_w from [-1, 1] to [near, far]. Here we use
// default near = 0 and far = 1, and undo the transformation to get the original z_over_w, then
// do our own transformation according to PICA specification.
out += "float z_over_w = 2.0 * gl_FragCoord.z - 1.0;\n";
out += "float depth = z_over_w * depth_scale + depth_offset;\n";
if (state.depthmap_enable == RasterizerRegs::DepthBuffering::WBuffering) {
out += "depth /= gl_FragCoord.w;\n";
@ -1195,7 +1198,9 @@ void main() {
texcoord0_w = vert_texcoord0_w;
normquat = vert_normquat;
view = vert_view;
gl_Position = vec4(vert_position.x, vert_position.y, -vert_position.z, vert_position.w);
gl_Position = vert_position;
gl_ClipDistance[0] = -vert_position.z; // fixed PICA clipping plane z <= 0
// TODO (wwylele): calculate gl_ClipDistance[1] from user-defined clipping plane
}
)";

View file

@ -68,6 +68,8 @@ OpenGLState::OpenGLState() {
draw.vertex_buffer = 0;
draw.uniform_buffer = 0;
draw.shader_program = 0;
clip_distance = {};
}
void OpenGLState::Apply() const {
@ -261,6 +263,17 @@ void OpenGLState::Apply() const {
glUseProgram(draw.shader_program);
}
// Clip distance
for (size_t i = 0; i < clip_distance.size(); ++i) {
if (clip_distance[i] != cur_state.clip_distance[i]) {
if (clip_distance[i]) {
glEnable(GL_CLIP_DISTANCE0 + i);
} else {
glDisable(GL_CLIP_DISTANCE0 + i);
}
}
}
cur_state = *this;
}

View file

@ -4,6 +4,7 @@
#pragma once
#include <array>
#include <glad/glad.h>
namespace TextureUnits {
@ -123,6 +124,8 @@ public:
GLuint shader_program; // GL_CURRENT_PROGRAM
} draw;
std::array<bool, 2> clip_distance; // GL_CLIP_DISTANCE
OpenGLState();
/// Get the currently active OpenGL state

View file

@ -125,10 +125,6 @@ void ProcessTriangle(const OutputVertex& v0, const OutputVertex& v1, const Outpu
{Math::MakeVec(f0, f0, f0, -f1), Math::Vec4<float24>(f0, f0, f0, EPSILON)}, // w = EPSILON
}};
// TODO: If one vertex lies outside one of the depth clipping planes, some platforms (e.g. Wii)
// drop the whole primitive instead of clipping the primitive properly. We should test if
// this happens on the 3DS, too.
// Simple implementation of the Sutherland-Hodgman clipping algorithm.
// TODO: Make this less inefficient (currently lots of useless buffering overhead happens here)
for (auto edge : clipping_edges) {

View file

@ -19,10 +19,9 @@ struct Vertex : Shader::OutputVertex {
// Linear interpolation
// factor: 0=this, 1=vtx
// Note: This function cannot be called after perspective divide
void Lerp(float24 factor, const Vertex& vtx) {
pos = pos * factor + vtx.pos * (float24::FromFloat32(1) - factor);
// TODO: Should perform perspective correct interpolation here...
quat = quat * factor + vtx.quat * (float24::FromFloat32(1) - factor);
color = color * factor + vtx.color * (float24::FromFloat32(1) - factor);
tc0 = tc0 * factor + vtx.tc0 * (float24::FromFloat32(1) - factor);
@ -30,12 +29,11 @@ struct Vertex : Shader::OutputVertex {
tc0_w = tc0_w * factor + vtx.tc0_w * (float24::FromFloat32(1) - factor);
view = view * factor + vtx.view * (float24::FromFloat32(1) - factor);
tc2 = tc2 * factor + vtx.tc2 * (float24::FromFloat32(1) - factor);
screenpos = screenpos * factor + vtx.screenpos * (float24::FromFloat32(1) - factor);
}
// Linear interpolation
// factor: 0=v0, 1=v1
// Note: This function cannot be called after perspective divide
static Vertex Lerp(float24 factor, const Vertex& v0, const Vertex& v1) {
Vertex ret = v0;
ret.Lerp(factor, v1);